OCTOBER TERM, 1999

															Syllabus

															STENBERG, ATTORNEY GENERAL OF NEBRASKA, ET AL. v. CARHART

															CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE EIGHTH
CIRCUIT No. 99-830. Argued April 25, 2000-Decided June 28, 2000 The Constitution offers basic protection to a woman's right to
choose whether to have an abortion. Roe v. Wade, 410 U. S. 113 ; Planned Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 .
Before fetal viability, a woman has a right to terminate her
pregnancy, id., at 870 (plurality opinion), and a state law
is unconstitutional if it imposes on the woman's decision an "undue
burden," i. e., if it has the purpose or effect of placing a
substantial obstacle in the woman's path, id., at 877.
Postviability, the State, in promoting its interest in the
potentiality of human life, may regulate, and even proscribe,
abortion except where "necessary, in appropriate medical judgment,
for the preservation of the [mother's] life or health." E. g., id., at 879. The Nebraska law at issue prohibits any "partial
birth abortion" unless that procedure is necessary to save the
mother's life. It defines "partial birth abortion" as a procedure
in which the doctor "partially delivers vaginally a living unborn
child before killing the ... child," and defines the latter phrase
to mean "intentionally delivering into the vagina a living unborn
child, or a substantial portion thereof, for the purpose of
performing a procedure that the [abortionist] knows will kill the
... child and does kill the ... child." Violation of the law is a
felony, and it provides for the automatic revocation of a convicted
doctor's state license to practice medicine. Respondent Carhart, a
Nebraska physician who performs abortions in a clinical setting,
brought this suit seeking a declaration that the statute violates
the Federal Constitution. The District Court held the statute
unconstitutional. The Eighth Circuit affirmed. Held: Nebraska's statute criminalizing the performance of
"partial birth abortion[s]" violates the Federal Constitution, as
interpreted in Casey and Roe. Pp. 922-946.

															(a) Because the statute seeks to ban one abortion method, the
Court discusses several different abortion procedures, as described
in the evidence below and the medical literature. During a
pregnancy's second trimester (12 to 24 weeks), the most common
abortion procedure is "dilation and evacuation" (D&E), which
involves dilation of the cervix, removal of at least some fetal
tissue using nonvacuum surgical instruments, and (after the 15th
week) the potential need for instrumental 915 dismemberment of the fetus or the collapse of fetal parts to
facilitate evacuation from the uterus. When such dismemberment is
necessary, it typically occurs as the doctor pulls a portion of the
fetus through the cervix into the birth canal. The risks of
mortality and complication that accompany D&E are significantly
lower than those accompanying induced labor procedures (the next
safest midsecond trimester procedures). A variation of D&E,
known as "intact D&E," is used after 16 weeks. It involves
removing the fetus from the uterus through the cervix "intact," i. e., in one pass rather than several passes. The intact
D&E proceeds in one of two ways, depending on whether the fetus
presents head first or feet first. The feet-first method is known
as "dilation and extraction" (D&X). D&X is ordinarily
associated with the term "partial birth abortion." The District
Court concluded that clear and convincing evidence established that
Carhart's D&X procedure is superior to, and safer than, the
D&E and other abortion procedures used during the relevant
gestational period in the 10 to 20 cases a year that present to
Carhart. Moreover, materials presented at trial emphasize the
potential benefits of the D&X procedure in certain cases. Pp.
923-929.

															(b) The Nebraska statute lacks the requisite exception "for the
preservation of the ... health of the mother." Casey, supra, at 879 (plurality opinion). The State may promote but not endanger
a woman's health when it regulates the methods of abortion. Pp.
929-938.

															(i) The Court rejects Nebraska's contention that there is no
need for a health exception here because safe alternatives remain
available and a ban on partial birth abortionJD&X would create
no risk to women's health. The parties strongly contested this
factual question in the District Court; and the findings and
evidence support Dr. Carhart. Pp. 931-933.

															(ii) Nebraska and its supporting amici respond with eight
arguments as to why the District Court's findings are irrelevant,
wrong, or applicable only in a tiny number of instances. Pp.
933-934.

															(iii) The eight arguments are insufficient to demonstrate that
Nebraska's law needs no health exception. For one thing, certain of
the arguments are beside the point. The D&X procedure's
relative rarity (argument (1)) is not highly relevant. The State
cannot prohibit a person from obtaining treatment simply by
pointing out that most people do not need it. And the fact that
only a "handful" of doctors use the procedure (argument (2)) may
reflect the comparative rarity of late second term abortions, the
procedure's recent development, the controversy surrounding it, or,
as Nebraska suggests, the procedure's lack of utility. For another
thing, the record responds to Nebraska's (and amici's) medically based arguments. As to argument (3), the District 916 Syllabus

															Court agreed that alternatives such as D&E and induced labor
are "safe," but found that the D&X method was safer in
the circumstances used by Carhart. As to argument (4)-that
testimony showed that the statutory ban would not increase a
woman's risk of several rare abortion complications-the District
Court simply relied on different expert testimony than the State.
Argument (5)-the assertion of amici Association of American
Physicians and Surgeons et al. that elements of the D&X
procedure may create special risks-is disputed by Carhart's amici, including the American College of Obstetricians and
Gynecologists (ACOG), which claims that the suggested alternative
procedures involve similar or greater risks of cervical and uterine
injury. Nebraska's argument (6) is right-there are no general
medical studies documenting the comparative safety of the various
abortion procedures. Nor does the Court deny the import of the
American Medical Association's (AMA) recommendation (argument (7))
that intact D&X not be used unless alternative procedures pose
materially greater risk to the woman. However, the Court cannot
read ACOG's qualification that it could not identify a circumstance
where D&X was the "only" life- or health-preserving option as
if, according to Nebraska's argument (8), it denied the potential
health-related need for D&X. ACOG has also asserted that
D&X can be the most appropriate abortion procedure and presents
a variety of potential safety advantages. Pp. 934-936.

															(iv) The upshot is a District Court finding that D&X
obviates health risks in certain circumstances, a highly plausible
record-based explanation of why that might be so, a division of
medical opinion over whether D&X is generally safer, and an
absence of controlled medical studies that would help answer these
medical questions. Given these circumstances, the Court believes
the law requires a health exception. For one thing, the word
"necessary" in Casey's phrase "necessary, in appropriate
medical judgment, for the ... health of the mother," 505 U. S., at
879, cannot refer to absolute proof or require unanimity of medical
opinion. Doctors often differ in their estimation of comparative
health risks and appropriate treatment. And Casey's words
"appropriate medical judgment" must embody the judicial need to
tolerate responsible differences of medical opinion. For another
thing, the division of medical opinion signals uncertainty. If
those who believe that D&X is a safer abortion method in
certain circumstances turn out to be right, the absence of a health
exception will place women at an unnecessary risk. If they are
wrong, the exception will simply turn out to have been unnecessary.
pp. 936-938.

															(c) The Nebraska statute imposes an "undue burden" on a woman's
ability to choose an abortion. See Casey, supra, at 874
(plurality opinion). Pp. 938-946. 917 (i) Nebraska does not deny that the statute imposes an "undue
burden" if it applies to the more commonly used D&E
procedure as well as to D&X. This Court agrees with the Eighth
Circuit that the D&E procedure falls within the statutory
prohibition of intentionally delivering into the vagina a living
fetus, or "a substantial portion thereof," for the purpose of
performing a procedure that the perpetrator knows will kill the
fetus. Because the evidence makes clear that D&E will often
involve a physician pulling an arm, leg, or other "substantial
portion" of a still living fetus into the vagina prior to the
fetus' death, the statutory terms do not to distinguish between
D&X and D&E. The statute's language does not track the
medical differences between D&E and D&X, but covers both. U
sing the law's statutory terms, it is impossible to distinguish
between D&E (where a foot or arm is drawn through the cervix)
and D&X (where the body up to the head is drawn through the
cervix). Both procedures can involve the introduction of a
"substantial portion" of a still living fetus, through the cervix,
into the vagina-the very feature of an abortion that leads to
characterizing such a procedure as involving "partial birth." Pp.
938-940.

															(ii) The Court rejects the Nebraska Attorney General's arguments
that the state law does differentiate between the two procedures-i. e., that the words "substantial portion" mean "the child up
to the head," such that the law is inapplicable where the physician
introduces into the birth canal anything less than the entire fetal
body-and that the Court must defer to his views. The Court's case
law makes clear that the Attorney General's narrowing
interpretation cannot be given controlling weight. For one thing,
this Court normally follows lower federalcourt interpretations of
state law, e. g., McMillian v. Monroe County, 520 U. S. 781 ,
786, and rarely reviews such an interpretation that is agreed upon
by the two lower federal courts. Virginia v. American
Booksellers Assn., Inc., 484 U. S. 383 , 395. Here,
the two lower courts both rejected the Attorney General's narrowing
interpretation. For another, the Court's precedent warns against
accepting as "authoritative" an Attorney General's interpretation
of state law where, as here, that interpretation does not bind the
state courts or local law enforcement. In Nebraska, elected county
attorneys have independent authority to initiate criminal
prosecutions. Some present prosecutors (and future Attorneys
General) might use the law at issue to pursue physicians who use
D&E procedures. Nor can it be said that the lower courts used
the wrong legal standard in assessing the Attorney General's
interpretation. The Eighth Circuit recognized its duty to give the
law a construction that would avoid constitutional doubt, but
nonetheless concluded that the Attorney General's interpretation
would twist the law's words, giving them a meaning they cannot
reasonably bear. 918 Syllabus

															The Eighth Circuit is far from alone in rejecting such a
narrowing interpretation, since 11 of the 12 federal courts that
have interpreted on the merits the model statutory language on
which the Nebraska law is based have found the language potentially
applicable to abortion procedures other than D&X. Regardless,
were the Court to grant the Attorney General's views "substantial
weight," it would still have to reject his interpretation, for it
conflicts with the statutory language. The statutory words,
"substantial portion," indicate that the statute does not include
the Attorney General's restriction-"the child up to the head." The
Nebraska Legislature's debates hurt the Attorney General's argument
more than they help it, indicating that as small a portion of the
fetus as a foot would constitute a "substantial portion." Even
assuming that the distinction the Attorney General seeks to draw
between the overall abortion procedure itself and the separate
procedure used to kill an unborn child would help him make the
D&E/D&X distinction he seeks, there is no language in the
statute that supports it. Although adopting his interpretation
might avoid the constitutional problem discussed above, the Court
lacks power do so where, as here, the narrowing construction is not
reasonable and readily apparent. E. g., Boos v. Barry, 485 U.
S. 312 , 330. Finally, the Court has never held that a federal
litigant must await a state-court construction or the development
of an established practice before bringing the federal suit. City of Lakewood v. Plain Dealer Publishing Co., 486 U. S. 750 ,
770, n. II. But any authoritative state-court construction is
lacking here. The Attorney General neither sought a narrowing
interpretation from the Nebraska Supreme Court nor asked the
federal courts to certify the interpretive question. Cf. Arizonans for Official English v. Arizona, 520 U. S.
43. Even were the Court inclined to certify the question now, it
could not do so because certification is appropriate only where the
statute is "fairly susceptible" to a narrowing construction, see Houston v. Hill, 482 U. S. 451 , 468-471,
as is not the case here. Moreover, the Nebraska Supreme Court
grants certification only if the certified question is
determinative of the cause, see id., at 471, as it would not
be here. In sum, because all those who perform abortion procedures
using the D&E method must fear prosecution, conviction, and
imprisonment, the Nebraska law imposes an undue burden upon a
woman's right to make an abortion decision. Pp. 940-946. 192 F.3d
1142 , affirmed.

															BREYER, J., delivered the OpInIOn of the Court, in which
STEVENS, O'CONNOR, SOUTER, and GINSBURG, JJ., joined. STEVENS, J.,
filed a concurring opinion, in which GINSBURG, J., joined, post, p. 946. O'CONNOR, J., filed a concurring opinion, post, p. 947. GINSBURG, J., filed a concurring 919 opinion, in which STEVENS, J., joined, post, p. 951.
REHNQUIST, C. J., post, p. 952, and SCALIA, J., post, p. 953, filed dissenting opinions. KENNEDY, J., filed a dissenting
opinion, in which REHNQUIST, C. J., joined, post, p. 956.
THOMAS, J., filed a dissenting opinion, in which REHNQUIST, C. J.,
and SCALIA, J., joined, post, p. 980. Don Stenberg, Attorney General of Nebraska, pro
se, argued the cause for petitioners. With him on the briefs
was

															Simon Heller argued the cause for respondent. With him on the
brief were Janet Benshoof, Priscilla J. Smith, Bonnie Scott
Jones, Jerry M. Hug, and Alan G. Stoler. * *Briefs of amici curiae urging reversal were filed for
the State of Louisiana et al. by Richard P. Ieyoub, Attorney
General of Louisiana, Roy A. M ongrue, Jr., Assistant
Attorney General, Dorinda C. Bordlee, Special
Assistant Attorney General, Mike Moore, Attorney General of
Mississippi, Nikolas T. Nikas, and Stephen M.
Crampton; for the State of Texas by John Cornyn, Attorney General, Andy Taylor, First Assistant Attorney
General, Linda S. Eads, Deputy Attorney General, Gregory S. Coleman, Solicitor General, and Julie
Caruthers Parsley, Deputy Solicitor General; for the State of
Wisconsin by James E. Doyle, Attorney General, and Susan
K. Ullman, Assistant Attorney General; for Agudath Israel of
America by David Zwiebel; for the American Center for Law
and Justice et al. by Jay Alan Sekulow, James M. Henderson, Sr.,
Walter M. Weber, Thomas P. Monaghan, Richard Thompson, and Edward L. White III; for the Association of American
Physicians and Surgeons et al. by Teresa Stanton Collett; for Family First by Paul Benjamin Linton; for Feminists for
Life of America et al. by Dwight G. Duncan; for the
Knights of Columbus by Pat A. Cipollone and Carl A.
Anderson; for the National Association of Prolife Nurses, Inc.,
by William C. Porth and Robert P. George; for
the National Right to Life Committee by James Bopp, Jr., Richard
E. Coleson, and Thomas J. Marzen; for the
Rutherford Institute by Thomas W Strahan, John W Whitehead, and Steven H. Aden; for the United States Catholic
Conference et al. by Mark E. Chopko and Michael F. Moses; and for Representative Charles T. Canady et al. by James Bopp, Jr., Richard E. Coleson, and Thomas J. Marzen. Briefs of amici curiae urging affirmance were filed for the
United States by Solicitor General Waxman, Deputy Solicitor General
Underwood, Paul R. Q. Wolfson, Harriet S. Rabb, Marcy J. Wilder, and Kenneth Y. Choe; for the State of California
by Bill Lockyer, Attorney General, Peter J. Siggins, Chief
Deputy Attorney General, and Patricia A. Wynne, 920 JUSTICE BREYER delivered the opinion of the Court.

															We again consider the right to an abortion. We understand the
controversial nature of the problem. Millions of Americans believe
that life begins at conception and consequently that an abortion is
akin to causing the death of an innocent child; they recoil at the
thought of a law that would permit it. Other millions fear that a
law that forbids abortion would condemn many American women to
lives that lack dignity, depriving them of equal liberty and
leading those with least resources to undergo illegal abortions
with the attendant risks of death and suffering. Taking account
of

															Special Assistant Attorney General; for the State of New York et
al. by Eliot Spitzer, Attorney General of New York, Preeta D. Bansal, Solicitor General, and Jennifer K.
Brown, Assistant Attorney General, Andrew Ketterer, Attorney General of Maine, Hardy Myers, Attorney General of
Oregon, and William H. Sorrell, Attorney General of Vermont;
for the American Civil Liberties Union et al. by Catherine
Weiss, Steven R. Shapiro, and Colleen K. Connell; for
the American College of Obstetricians and Gynecologists et al. by Adam L. Frank, A. Stephen Hut, Jr., and Matthew A.
Brill; for the Naral Foundation et al. by James P. Joseph,
Nancy L. Perkins, and Elizabeth Arndorfer; for Planned
Parenthood of Wisconsin et al. by Roger K. Evans, Eve C. Gartner, and Dara Klassel; for the Religious
Coalition for Reproductive Choice et al. by Carrie Y. Flaxman; for Seventy-five Organizations Committed to Women's
Equality by Susan Frietsche, Carol E. Tracy, Martha F. Davis, Roslyn Powell, and Yolanda S. Wu; and
for Senator Barbara Boxer et al. by Robert Lewin, Kevin J. Curnin, Claude G. Szyfer, and Robert
Abrams. Briefs of amici curiae were filed by the Commonwealth of
Virginia et al. by Mark L. Earley, Attorney General of
Virginia, William H. Hurd, Solicitor General, and Daniel J. Poynor, Alison P. Landry, and Anthony P. Meredith, Assistant Attorneys General, Claire J. V. Richards, James Bopp, Jr., Richard E.
Coleson, Thomas J. Marzen, Richard F. Collier,
Jr., and by the Attorneys General for their respective States
as follows: Bill Pryor of Alabama, Alan G. Lance of Idaho, James E. Ryan of Illinois, Thomas J. Miller of Iowa, Jennifer M.
Granholm of Michigan, Heidi Heitkamp of North Dakota, Betty D. Montgomery of Ohio, D. Michael Fisher of
Pennsylvania, Charlie Condon of South Carolina, Mark
Barnett of South Dakota, and Jan Graham of Utah; and for
the Family Research Council by Teresa R. Wagner. 921 these virtually irreconcilable points of view, aware that
constitutionallaw must govern a society whose different members
sincerely hold directly opposing views, and considering the matter
in light of the Constitution's guarantees of fundamental individual
liberty, this Court, in the course of a generation, has determined
and then redetermined that the Constitution offers basic protection
to the woman's right to choose. Roe v. Wade, 410 U. S. 113 (1973); Planned Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 (1992). We shall not revisit those legal principles. Rather, we
apply them to the circumstances of this case.

															Three established principles determine the issue before us.

															We shall set them forth in the language of the joint opinion in Casey. First, before "viability ... the woman has a right to
choose to terminate her pregnancy." Id., at 870 (plurality
opinion).

															Second, "a law designed to further the State's interest in fetal
life which imposes an undue burden on the woman's decision before
fetal viability" is unconstitutional. Id., at 877. An "undue
burden is ... shorthand for the conclusion that a state regulation
has the purpose or effect of placing a substantial obstacle in the
path of a woman seeking an abortion of a nonviable fetus." Ibid. Third, "'subsequent to viability, the State in promoting its
interest in the potentiality of human life may, if it chooses,
regulate, and even proscribe, abortion except where it is
necessary, in appropriate medical judgment, for the preservation of
the life or health of the mother.'" Id., at 879 (quoting Roe v. Wade, supra, at 164-165).

															We apply these principles to a Nebraska law banning "partial
birth abortion." The statute reads as follows: "No partial birth abortion shall be performed in this state,
unless such procedure is necessary to save the life of the mother
whose life is endangered by a physical disorder, physical illness,
or physical injury, including a life-endangering physical condition
caused by or aris- 922 ing from the pregnancy itself." Neb. Rev. Stat. Ann. § 28-328(1)
(Supp. 1999).

															The statute defines "partial birth abortion" as: "an abortion procedure in which the person performing the
abortion partially delivers vaginally a living unborn child before
killing the unborn child and completing the delivery." §
28-326(9). It further defines "partially delivers vaginally a living unborn
child before killing the unborn child" to mean "deliberately and intentionally delivering into the vagina a
living unborn child, or a substantial portion thereof, for the
purpose of performing a procedure that the person performing such
procedure knows will kill the unborn child and does kill the unborn
child." Ibid. The law classifies violation of the statute as a "Class III
felony" carrying a prison term of up to 20 years, and a fine of up
to $25,000. §§ 28-328(2), 28-105. It also provides for the
automatic revocation of a doctor's license to practice medicine in
Nebraska. § 28-328(4).

															We hold that this statute violates the Constitution.

															I A

															Dr. Leroy Carhart is a Nebraska physician who performs abortions
in a clinical setting. He brought this lawsuit in Federal District
Court seeking a declaration that the Nebraska statute violates the
Federal Constitution, and asking for an injunction forbidding its
enforcement. After a trial on the merits, during which both sides
presented several expert witnesses, the District Court held the
statute unconstitutional. 11 F. Supp. 2d 1099 (Neb. 1998). On
appeal, the Eighth Circuit affirmed. 192 F.3d
1142 (1999); cf. Hope Clinic v. Ryan, 195 F.3d
857 (CA7 1999) (en banc) (consider- 923 ing a similar statute, but reaching a different legal
conclusion). We granted certiorari to consider the matter.

															B

															Because Nebraska law seeks to ban one method of aborting a
pregnancy, we must describe and then discuss several different
abortion procedures. Considering the fact that those procedures
seek to terminate a potential human life, our discussion may seem
clinically cold or callous to some, perhaps horrifying to others.
There is no alternative way, however, to acquaint the reader with
the technical distinctions among different abortion methods and
related factual matters, upon which the outcome of this case
depends. For that reason, drawing upon the findings of the trial
court, underlying testimony, and related medical texts, we shall
describe the relevant methods of performing abortions in technical
detail.

															The evidence before the trial court, as supported or
supplemented in the literature, indicates the following:

															1. About 90% of all abortions performed in the United States
take place during the first trimester of pregnancy, before 12 weeks
of gestational age. Centers for Disease Control and Prevention,
Abortion Surveillance-United States, 1996, p. 41 (July 30, 1999)
(hereinafter Abortion Surveillance). During the first trimester,
the predominant abortion method is "vacuum aspiration," which
involves insertion of a vacuum tube (cannula) into the uterus to
evacuate the contents. Such an abortion is typically performed on
an outpatient basis under local anesthesia. 11 F. Supp. 2d, at
1102; Obstetrics: Normal & Problem Pregnancies 1253-1254 (S.
Gabbe, J. Niebyl, & J. Simpson eds. 3d ed. 1996). Vacuum
aspiration is considered particularly safe. The procedure's
mortality rates for first trimester abortion are, for example, 5 to
10 times lower than those associated with carrying the fetus to
term. Complication rates are also low. Id., at 1251; Lawson
et al., Abortion Mortality, United 924 States, 1972 through 1987, 171 Am. J. Obstet. Gynecol. 1365,
1368 (1994); M. Paul et al., A Clinicians Guide to Medical and
Surgical Abortion 108-109 (1999) (hereinafter Medical and Surgical
Abortion). As the fetus grows in size, however, the vacuum
aspiration method becomes increasingly difficult to use. 11 F.
Supp. 2d, at 1102-1103; Obstetrics:

															Normal & Problem Pregnancies, supra, at 1268.

															2. Approximately 10% of all abortions are performed during the
second trimester of pregnancy (12 to 24 weeks). Abortion
Surveillance 41. In the early 1970's, inducing labor through the
injection of saline into the uterus was the predominant method of
second trimester abortion. Id., at 8; Planned Parenthood
of Central Mo. v. Danforth, 428 U. S. 52 , 76 (1976).
Today, however, the medical profession has switched from medical
induction of labor to surgical procedures for most second trimester
abortions. The most commonly used procedure is called "dilation and
evacuation" (D&E). That procedure (together with a modified
form of vacuum aspiration used in the early second trimester)
accounts for about 95% of all abortions performed from 12 to 20
weeks of gestational age. Abortion Surveillance 41.

															3. D&E "refers generically to transcervical procedures
performed at 13 weeks gestation or later." American Medical
Association, Report of Board of Trustees on Late-Term Abortion,
App. 490 (hereinafter AMA Report). The AMA Report, adopted by the
District Court, describes the process as follows.

															Between 13 and 15 weeks of gestation: "D&E is similar to vacuum aspiration except that the cervix
must be dilated more widely because surgical instruments are used
to remove larger pieces of tissue. Osmotic dilators are usually
used. Intravenous fluids and an analgesic or sedative may be
administered. A local anesthetic such as a paracervical block may
be administered, dilating agents, if used, are removed and
instruments are inserted through the cervix into the 925 uterus to removal fetal and placental tissue. Because fetal
tissue is friable and easily broken, the fetus may not be removed
intact. The walls of the uterus are scraped with a curette to
ensure that no tissue remains." Id., at 490-491. After 15 weeks: "Because the fetus is larger at this stage of gestation
(particularly the head), and because bones are more rigid,
dismemberment or other destructive procedures are more likely to be
required than at earlier gestational ages to remove fetal and
placental tissue." Id., at 491. After 20 weeks: "Some physicians use intrafetal potassium chloride or digoxin to
induce fetal demise prior to a late D&E (after 20 weeks), to
facilitate evacuation." Id., at 491-492. There are variations in D&E operative strategy; compare ibid. with W. Hern, Abortion Practice 146-156 (1984), and
Medical and Surgical Abortion 133-135. However, the common points
are that D&E involves (1) dilation of the cervix; (2) removal
of at least some fetal tissue using nonvacuum instruments; and (3)
(after the 15th week) the potential need for instrumental
disarticulation or dismemberment of the fetus or the collapse of
fetal parts to facilitate evacuation from the uterus.

															4. When instrumental disarticulation incident to D&E is
necessary, it typically occurs as the doctor pulls a portion of the
fetus through the cervix into the birth canal. Dr. Carhart
testified at trial as follows:

															"Dr. Carhart: 'The dismemberment occurs betweenthe traction of
my instrument and the counter traction of the internal os of the
cervix .... "Counsel: 'So the dismemberment occurs after you pulled a part
of the fetus through the cervix, is that correct? 926 "Dr. Carhart: 'Exactly. Because you're using-The cervix has two
strictures or two rings, the internal os and the external os ...
that's what's actually doing the dismembering ...

															"Counsel: 'When we talked before or talked before about a
D&E, that is not-where there is not intention to do it intact,
do you, in that situation, dismember the fetus in utero first, then
remove portions?

															"Dr. Carhart: 'I don't think so .... I don't know of any way
that one could go in and intentionally dismember the fetus in the
uterus .... It takes something that restricts the motion of the
fetus against what you're doing before you're going to get
dismemberment.'" 11 F. Supp. 2d, at 1104.

															Dr. Carhart's specification of the location of fetal
disarticulation is consistent with other sources. See Medical and
Surgical Abortion 135; App. in Nos. 98-3245 and 98-3300 (CA8), p. 683, (testimony of Dr. Phillip Stubblefield) ("Q:
SO you don't actually dismember the fetus in utero, then take the
pieces out? A: No").

															5. The D&E procedure carries certain risks. The use of
instruments within the uterus creates a danger of accidental
perforation and damage to neighboring organs. Sharp fetal bone
fragments create similar dangers. And fetal tissue accidentally
left behind can cause infection and various other complications.
See 11 F. Supp. 2d, at 1110; Gynecologic, Obstetric, and Related
Surgery 1045 (D. Nichols & D. ClarkePearson eds. 2d ed. 2000);
F. Cunningham et aI., Williams Obstetrics 598 (20th ed. 1997).
Nonetheless studies show that the risks of mortality and
complication that accompany the D&E procedure between the 12th
and 20th weeks of gestation are significantly lower than those
accompanying induced labor procedures (the next safest midsecond
trimester procedures). See Gynecologic, Obstetric, and Related
Surgery, supra, at 1046; AMA Report, App. 495, 496;
Medical 927 and Surgical Abortion 139, 142; Lawson, 171 Am. J. Obstet.
Gynecol., at 1368.

															6. At trial, Dr. Carhart and Dr. Stubblefield described a
variation of the D&E procedure, which they referred to as an
"intact D&E." See 11 F. Supp. 2d, at 1105, 1111. Like other
versions of the D&E technique, it begins with induced dilation
of the cervix. The procedure then involves removing the fetus from
the uterus through the cervix "intact," i. e., in one pass,
rather than in several passes. Ibid. It is used after 16
weeks at the earliest, as vacuum aspiration becomes ineffective and
the fetal skull becomes too large to pass through the cervix. Id., at 1105. The intact D&E proceeds in one of two
ways, depending on the presentation of the fetus. If the fetus
presents head first (a vertex presentation), the doctor collapses
the skull; and the doctor then extracts the entire fetus through
the cervix. If the fetus presents feet first (a breech
presentation), the doctor pulls the fetal body through the cervix,
collapses the skull, and extracts the fetus through the cervix. Ibid. The breech extraction version of the intact D&E is
also known commonly as "dilation and extraction," or D&X. Id., at 1112. In the late second trimester, vertex, breech,
and traverse/ compound (sideways) presentations occur in roughly
similar proportions. Medical and Surgical Abortion 135; 11 F. Supp.
2d, at 1108.

															7. The intact D&E procedure can also be found described in
certain obstetric and abortion clinical textbooks, where two
variations are recognized. The first, as just described, calls for
the physician to adapt his method for extracting the intact fetus
depending on fetal presentation. See Gynecologic, Obstetric, and
Related Surgery, supra, at 1043; Medical and Surgical
Abortion 136-137. This is the method used by Dr. Carhart. See 11 F.
Supp. 2d, at 1105. A slightly different version of the intact
D&E procedure, associated with Dr. Martin Haskell, calls for
conversion to a breech presentation in all cases. See Gynecologic,
Obstetric, and Related 928 Surgery, supra, at 1043 (citing M. Haskell, Dilation and
Extraction for Late Second Trimester Abortion (1992), in 139 Congo
Rec. 8605 (1993)).

															8. The American College of Obstetricians and Gynecologists
describes the D&X procedure in a manner corresponding to a
breech-conversion intact D&E, including the following
steps: "1. deliberate dilatation of the cervix, usually over a sequence
of days; "2. instrumental conversion of the fetus to a footling
breech; "3. breech extraction of the body excepting the head; and "4. partial evacuation of the intracranial contents of a living
fetus to effect vaginal delivery of a dead but otherwise intact
fetus." American College of Obstetricians and Gynecologists
Executive Board, Statement on Intact Dilation and Extraction (Jan.
12, 1997) (hereinafter ACOG Statement), App. 599-560. Despite the technical differences we have just described, intact
D&E and D&X are sufficiently similar for us to use the
terms interchangeably.

															9. Dr. Carhart testified he attempts to use the intact D&E
procedure during weeks 16 to 20 because (1) it reduces the dangers
from sharp bone fragments passing through the cervix, (2) minimizes
the number of instrument passes needed for extraction and lessens
the likelihood of uterine perforations caused by those instruments,
(3) reduces the likelihood of leaving infection-causing fetal and
placental tissue in the uterus, and (4) could help to prevent
potentially fatal absorption of fetal tissue into the maternal
circulation. See 11 F. Supp. 2d, at 1107. The District Court made
no findings about the D&X procedure's overall safety. Id., at 1126, n. 39. The District Court concluded, however,
that "the evidence is both clear and convincing that Carhart's 929 D&X procedure is superior to, and safer than, the ... other
abortion procedures used during the relevant gestational period in
the 10 to 20 cases a year that present to Dr. Carhart." Id., at 1126.

															10. The materials presented at trial referred to the potential
benefits of the D&X procedure in circumstances involving
nonviable fetuses, such as fetuses with abnormal fluid accumulation
in the brain (hydrocephaly). See 11 F. Supp. 2d, at 1107 (quoting
AMA Report, App. 492 (" 'Intact D&X may be preferred by some
physicians, particularly when the fetus has been diagnosed with
hydrocephaly or other anomalies incompatible with life outside the
womb' ")); see also Grimes, The Continuing Need for Late Abortions,
280 JAMA 747, 748 (Aug. 26, 1998) (D&X "may be especially
useful in the presence of fetal anomalies, such as hydrocephalus,"
because its reduction of the cranium allows "a smaller diameter to
pass through the cervix, thus reducing risk of cervical injury").
Others have emphasized its potential for women with prior uterine
scars, or for women for whom induction of labor would be
particularly dangerous. See Women's Medical Professional
Corp. v. Voinovich, 911 F. Supp. 2d 1051, 1067 (SD Ohio
1995); Evans v. Kelley, 977 F. Supp. 2d 1283, 1296
(ED Mich. 1997).

															11. There are no reliable data on the number of D&X
abortions performed annually. Estimates have ranged between 640 and
5,000 per year. Compare Henshaw, Abortion Incidence and Services in
the United States, 1995-1996, 30 Family Planning Perspectives 263,
268 (1998), with Joint Hearing on S. 6 and H. R. 929 before the
Senate Committee on the Judiciary and the Subcommittee on the
Constitution of the House Committee on the Judiciary, 105th Cong.,
1st Sess., 46 (1997).

															II

															The question before us is whether Nebraska's statute, making
criminal the performance of a "partial birth abortion," violates
the Federal Constitution, as interpreted in 930 Planned Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 (1992), and Roe v. Wade, 410 U. S. 113 (1973). We
conclude that it does for at least two independent reasons. First,
the law lacks any exception "'for the preservation of the ...
health of the mother.''' Casey, 505 U. S., at 879 (plurality
opinion). Second, it "imposes an undue burden on a woman's ability"
to choose a D&E abortion, thereby unduly burdening the right to
choose abortion itself. Id., at 874. We shall discuss each
of these reasons in turn.

															A

															The Casey plurality opinion reiterated what the Court
held in Roe; that" 'subsequent to viability, the State in
promoting its interest in the potentiality of human life may, if it
chooses, regulate, and even proscribe, abortion except where it
is necessary, in appropriate medical judgment, for the preservation
of the life or health of the mother.''' 505 U. S., at 879
(quoting Roe, supra, at 164-165) (emphasis added).

															The fact that Nebraska's law applies both previability and
postviability aggravates the constitutional problem presented. The
State's interest in regulating abortion previability is
considerably weaker than postviability. See Casey, supra, at
870. Since the law requires a health exception in order to validate
even a postviability abortion regulation, it at a minimum requires
the same in respect to previability regulation. See Casey,
supra, at 880 (majority opinion) (assuming need for health
exception previability); see also Harris v. McRae, 448 U. S. 297 ,
316 (1980).

															The quoted standard also depends on the state regulations
"promoting [the State's] interest in the potentiality of human
life." The Nebraska law, of course, does not directly further an
interest "in the potentiality of human life" by saving the fetus in
question from destruction, as it regulates only a method of
performing abortion. Nebraska describes its interests differently.
It says the law" 'show[s] concern for the life of the unborn,'"
"prevent[s] cruelty to partially born chil- 931 dren," and "preserve[s] the integrity of the medical
profession." Brief for Petitioners 48. But we cannot see how the
interest-related differences could make any difference to the
question at hand, namely, the application of the "health"
requirement.

															Consequently, the governing standard requires an exception
"where it is necessary, in appropriate medical judgment for the
preservation of the life or health of the mother," Casey,
supra, at 879, for this Court has made clear that a State may
promote but not endanger a woman's health when it regulates the
methods of abortion. Thornburgh v. American College of
Obstetricians and Gynecologists, 476 U. S. 747 , 768-769
(1986); Colautti v. Franklin, 439 U. S. 379 , 400 (1979); Danforth, 428 U. S., at 76-79; Doe v. Bolton, 410 U.
S. 179 , 197 (1973).

															JUSTICE THOMAS says that the cases just cited limit this
principle to situations where the pregnancy itself creates a
threat to health. See post, at 1010. He is wrong. The cited
cases, reaffirmed in Casey, recognize that a State cannot
subject women's health to significant risks both in that context, and also where state regulations force women to use riskier
methods of abortion. Our cases have repeatedly invalidated statutes
that in the process of regulating the methods of abortion,
imposed significant health risks. They make clear that a risk to a
women's health is the same whether it happens to arise from
regulating a particular method of abortion, or from barring
abortion entirely. Our holding does not go beyond those cases, as
ratified in Casey. 1

															Nebraska responds that the law does not require a health
exception unless there is a need for such an exception. And here
there is no such need, it says. It argues that "safe alternatives
remain available" and "a ban on partial-birth abortion/D&X
would create no risk to the health of women." Brief for Petitioners
29, 40. The problem for Nebraska is 932 that the parties strongly contested this factual question in the
trial court below; and the findings and evidence support Dr.
Carhart. The State fails to demonstrate that banning D&X
without a health exception may not create significant health risks
for women, because the record shows that significant medical
authority supports the proposition that in some circumstances,
D&X would be the safest procedure.

															We shall reiterate in summary form the relevant findings and
evidence. On the basis of medical testimony the District Court
concluded that "Carhart's D&X procedure is ... safer tha[n] the
D&E and other abortion procedures used during the relevant
gestational period in the 10 to 20 cases a year that present to Dr.
Carhart." 11 F. Supp. 2d, at 1126. It found that the D&X
procedure permits the fetus to pass through the cervix with a
minimum of instrumentation. Ibid. It thereby "reduces operating time, blood loss and risk of infection;
reduces complications from bony fragments; reduces
instrument-inflicted damage to the uterus and cervix; prevents the
most common causes of maternal mortality (DIC and amniotic fluid
embolus); and eliminates the possibility of 'horrible
complications' arising from retained fetal parts." Ibid. The District Court also noted that a select panel of the
American College of Obstetricians and Gynecologists concluded that
D&X "'may be the best or most appropriate procedure in a
particular circumstance to save the life or preserve the health of
a woman.'" Id., at 1105, n. 10 (quoting ACOG Statement, App.
600-601) (but see an important qualification, infra, at
934). With one exception, the federal trial courts that have heard
expert evidence on the matter have reached similar factual
conclusions. See Rhode Island Medical Soc. v. Whitehouse, 66 F. Supp. 2d 288, 314 (RI 1999); A Choice
for Women v. Butterworth, 54 F. Supp. 2d 1148, 1153,
1156 (SD Fla. 1998); Causeway Medical Suite v. Foster, 43 F. Supp. 2d 604,613-614 (ED La. 1999); Richmond 933 Medical Center for Women v. Gilmore, 11 F. Supp.
2d 795, 827, n. 40 (ED Va. 1998); Hope Clinic v. Ryan, 995 F. Supp. 2d 847, 852 (ND Ill. 1998), vacated, 195 F.3d
857 (CA7 1999), cert. pending, No. 99-1152; Voinovich, 911 F. Supp. 2d, at 1069-1070; Kelley, 977
F. Supp. 2d, at 1296; but see Planned Parenthood of Wis. v. Doyle, 44 F. Supp. 2d 975, 980 (WD Wis.), vacated, 195 F.3d
857 (CA7 1999). 2

															Nebraska, along with supporting amici, replies that these
findings are irrelevant, wrong, or applicable only in a tiny number
of instances. It says (1) that the D&X procedure is
"little-used," (2) by only "a handful of doctors." Brief for
Petitioners 32. It argues (3) that D&E and labor induction are
at all times "safe alternative procedures." Id., at 36. It
refers to the testimony of petitioners' medical expert, who
testified (4) that the ban would not increase a woman's risk of
several rare abortion complications (disseminated intravascular
coagulopathy and amniotic fluid embolus), id., at 37;
App.642-644.

															The Association of American Physicians and Surgeons et aI., amici supporting Nebraska, argue (5) that elements of the
D&X procedure may create special risks, including cervical
incompetence caused by overdilitation, injury caused by conversion
of the fetal presentation, and dangers arising from the "blind" use
of instrumentation to pierce the fetal skull while lodged in the
birth canal. See Brief for Association of American Physicians and
Surgeons et al. as Amici Curiae 21-23; see also Sprang &
Neerhof, Rationale for Banning Abortions Late in Pregnancy, 280
JAMA 744, 746 (Aug. 26, 1998).

															Nebraska further emphasizes (6) that there are no medical
studies "establishing the safety of the partial-birth abortion!
D&X procedure," Brief for Petitioners 39, and "no medical
studies comparing the safety of partial-birth abortion!D&X to
other abortion procedures," ibid. It points to, id., at 35, 934 (7) an American Medical Association policy statement that
"'there does not appear to be any identified situation in which
intact D&X is the only appropriate procedure to induce
abortion,'" Late Term Pregnancy Termination Techniques, AMA Policy
H-5.982 (1997). And it points out (8) that the American College of
Obstetricians and Gynecologists qualified its statement that
D&X "may be the best or most appropriate procedure," by adding
that the panel "could identify no circumstances under which [the
D&X] procedure ... would be the only option to save the life or
preserve the health of the woman." App.600-601.

															3

															We find these eight arguments insufficient to demonstrate that
Nebraska's law needs no health exception. For one thing, certain of
the arguments are beside the point. The D&X procedure's
relative rarity (argument (1)) is not highly relevant. The D&X
is an infrequently used abortion procedure; but the health
exception question is whether protecting women's health requires an
exception for those infrequent occasions. A rarely used treatment
might be necessary to treat a rarely occurring disease that could
strike anyone-the State cannot prohibit a person from obtaining
treatment simply by pointing out that most people do not need it.
Nor can we know whether the fact that only a "handful" of doctors
use the procedure (argument (2)) reflects the comparative rarity of
late second term abortions, the procedure's recent development,
Gynecologic, Obstetric, and Related Surgery, at 1043, the
controversy surrounding it, or, as Nebraska suggests, the
procedure's lack of utility.

															For another thing, the record responds to Nebraska's (and amici's) medically based arguments. In respect to argument
(3), for example, the District Court agreed that alternatives, such
as D&E and induced labor, are "safe" but found that the D&X
method was significantly safer in certain circumstances. 11
F. Supp. 2d, at 1125-1126. In respect to 935 argument (4), the District Court simply relied on different
expert testimony-testimony stating that" '[a]nother advantage of
the Intact D&E is that it eliminates the risk of embolism of
cerebral tissue into the woman's blood stream.'" Id., at
1124 (quoting Hearing on H. R. 1833 before the Senate Committee on
the Judiciary, 104th Cong., 1st Sess., 260 (1995) (statement of W.
Hern).

															In response to amici's argument (5), the American College
of Obstetricians and Gynecologists, in its own amici brief,
denies that D&X generally poses risks greater than the
alternatives. It says that the suggested alternative procedures
involve similar or greater risks of cervical and uterine injury,
for "D&E procedures, involve similar amounts of dilitation" and
"of course childbirth involves even greater cervical dilitation."
Brief for American College of Obstetricians and Gynecologists et
al. as Amici Curiae 23. The College points out that Dr.
Carhart does not reposition the fetus thereby avoiding any risks
stemming from conversion to breech presentation, and that, as
compared with D&X, D&E involves the same, if not greater,
"blind" use of sharp instruments in the uterine cavity. Id., at 23-24.

															We do not quarrel with Nebraska's argument (6), for Nebraska is
right. There are no general medical studies documenting comparative
safety. N either do we deny the import of the American Medical
Association's statement (argument (7))-even though the State does
omit the remainder of that statement: "The AMA recommends that the
procedure not be used unless alternative procedures pose
materially greater risk to the woman." Late Term Pregnancy
Termination Techniques, AMA Policy H-5.982 (emphasis added).

															We cannot, however, read the American College of Obstetricians
and Gynecologists panel's qualification (that it could not
"identify" a circumstance where D&X was the "only" life- or
health-preserving option) as if, according to Nebraska's argument
(8), it denied the potential health-related need 936 for D&X. That is because the College writes the following in
its amici brief: "Depending on the physician's skill and experience, the D&X
procedure can be the most appropriate abortion procedure for some
women in some circumstances. D&X presents a variety of
potential safety advantages over other abortion procedures used
during the same gestational period. Compared to D&Es involving
dismemberment, D&X involves less risk of uterine perforation or
cervical laceration because it requires the physician to make fewer
passes into the uterus with sharp instruments and reduces the
presence of sharp fetal bone fragments that can injure the uterus
and cervix. There is also considerable evidence that D&X
reduces the risk of retained fetal tissue, a serious abortion
complication that can cause maternal death, and that D&X
reduces the incidence of a 'free floating' fetal head that can be
difficult for a physician to grasp and remove and can thus cause
maternal injury. That D&X procedures usually take less time
than other abortion methods used at a comparable stage of pregnancy
can also have health advantages. The shorter the procedure, the
less blood loss, trauma, and exposure to anesthesia. The intuitive
safety advantages of intact D&E are supported by clinical
experience. Especially for women with particular health conditions,
there is medical evidence that D&X may be safer than available
alternatives." Brief for American College of Obstetricians and
Gynecologists et al. as Amici Curiae 21-22 (citation and
footnotes omitted). 4

															The upshot is a District Court finding that D&X
significantly obviates health risks in certain circumstances, a
highly plausible record-based explanation of why that might be so,
a division of opinion among some medical experts over 937 whether D&X is generally safer, and an absence of controlled
medical studies that would help answer these medical questions.
Given these medically related evidentiary circumstances, we believe
the law requires a health exception.

															The word "necessary" in Casey's phrase "necessary, in
appropriate medical judgment, for the preservation of the life or
health of the mother," 505 U. S., at 879 (internal quotation marks
omitted), cannot refer to an absolute necessity or to absolute
proof. Medical treatments and procedures are often considered
appropriate (or inappropriate) in light of estimated comparative
health risks (and health benefits) in particular cases. Neither can
that phrase require unanimity of medical opinion. Doctors often
differ in their estimation of comparative health risks and
appropriate treatment. And Casey's words "appropriate
medical judgment" must embody the judicial need to tolerate
responsible differences of medical opinion-differences of a sort
that the American Medical Association and American College of
Obstetricians and Gynecologists' statements together indicate are
present here.

															For another thing, the division of medical opinion about the
matter at most means uncertainty, a factor that signals the
presence of risk, not its absence. That division here involves
highly qualified knowledgeable experts on both sides of the issue.
Where a significant body of medical opinion believes a procedure
may bring with it greater safety for some patients and explains the
medical reasons supporting that view, we cannot say that the
presence of a different view by itself proves the contrary. Rather,
the uncertainty means a significant likelihood that those who
believe that D&X is a safer abortion method in certain
circumstances may turn out to be right. If so, then the absence of
a health exception will place women at an unnecessary risk of
tragic health consequences. If they are wrong, the exception will
simply turn out to have been unnecessary.

															In sum, Nebraska has not convinced us that a health exception is
"never necessary to preserve the health of 938 women." Reply Brief for Petitioners 4. Rather, a statute that
altogether forbids D&X creates a significant health risk. The
statute consequently must contain a health exception. This is not
to say, as JUSTICE THOMAS and JUSTICE KENNEDY claim, that a State
is prohibited from proscribing an abortion procedure whenever a
particular physician deems the procedure preferable. By no means
must a State grant physicians "unfettered discretion" in their
selection of abortion methods. Post, at 969 (KENNEDY, J.,
dissenting). But where substantial medical authority supports the
proposition that banning a particular abortion procedure could
endanger women's health, Casey requires the statute to
include a health exception when the procedure is "'necessary, in
appropriate medical judgment, for the preservation of the life or
health of the mother.'" 505 U. S., at 879. Requiring such an
exception in this case is no departure from Casey, but
simply a straightforward application of its holding.

															B

															The Eighth Circuit found the Nebraska statute unconstitutional
because, in Casey's words, it has the "effect of placing a
substantial obstacle in the path of a woman seeking an abortion of
a nonviable fetus." Id., at 877. It thereby places an "undue
burden" upon a woman's right to terminate her pregnancy before
viability. Ibid. Nebraska does not deny that the statute
imposes an "undue burden" ifit applies to the more commonly
used D&E procedure as well as to D&X. And we agree with the
Eighth Circuit that it does so apply.

															Our earlier discussion of the D&E procedure, supra, at 924-926, shows that it falls within the statutory prohibition.
The statute forbids "deliberately and intentionally delivering into
the vagina a living unborn child, or a substantial portion thereof,
for the purpose of performing a procedure that the person
performing such procedure knows will kill the unborn child." Neb.
Rev. Stat. Ann. § 28-326(9) (Supp. 1999). We 939 do not understand how one could distinguish, using this
language, between D&E (where a foot or arm is drawn through the
cervix) and D&X (where the body up to the head is drawn through
the cervix). Evidence before the trial court makes clear that
D&E will often involve a physician pulling a "substantial
portion" of a still living fetus, say, an arm or leg, into the
vagina prior to the death of the fetus. 11 F. Supp. 2d, at 1128; id., at 1128-1130. Indeed D&E involves dismemberment
that commonly occurs only when the fetus meets resistance that
restricts the motion of the fetus: "The dismemberment occurs
between the traction of ... [the] instrument and the
counter-traction of the internal os of the cervix." Id., at
1128. And these events often do not occur until after a portion of
a living fetus has been pulled into the vagina. Id., at
1104; see also Medical and Surgical Abortion 135 ("During the
mid-second trimester, separation of the fetal corpus may occur when
the fetus is drawn into the lower uterine segment, where
compression and traction against the en do cervix facilitates
disarticulation").

															Even if the statute's basic aim is to ban D&X, its language
makes clear that it also covers a much broader category of
procedures. The language does not track the medical differences
between D&E and D&X-though it would have been a simple
matter, for example, to provide an exception for the performance of
D&E and other abortion procedures. E. g., Kan. Stat.
Ann. § 65-6721(b)(1) (Supp. 1999). Nor does the statute anywhere
suggest that its application turns on whether a portion of the
fetus' body is drawn into the vagina as part of a process to
extract an intact fetus after collapsing the head as opposed to a
process that would dismember the fetus. Thus, the dissenters'
argument that the law was generally intended to bar D&X can be
both correct and irrelevant. The relevant question is not whether the legislature wanted to ban D&X; it is whether the
law was intended to apply only to D&X. The plain
language covers both procedures. A rereading of this opinion, supra, at 924-929, as 940 well as JUSTICE THOMAS' dissent, post, at 984-987, will
make clear why we can find no difference, in terms of this statute, between the D&X procedure as described and the D&E
procedure as it might be performed. (In particular, compare post, at 984-986 (THOMAS, J., dissenting), with post, at 986989 (THOMAS, J., dissenting).) Both procedures can involve
the introduction of a "substantial portion" of a still living
fetus, through the cervix, into the vagina-the very feature of an
abortion that leads JUSTICE THOMAS to characterize such a procedure
as involving "partial birth."

															The Nebraska State Attorney General argues that the statute does
differentiate between the two procedures. He says that the
statutory words "substantial portion" mean "the child up to the
head." He consequently denies the statute's application where the
physician introduces into the birth canal a fetal arm or leg or
anything less than the entire fetal body. Brief for Petitioners 20.
He argues further that we must defer to his views about the meaning
of the state statute. Id., at 12-13.

															We cannot accept the Attorney General's narrowing interpretation
of the Nebraska statute. This Court's case law makes clear that we
are not to give the Attorney General's interpretative views
controlling weight. For one thing, this Court normally follows
lower federal-court interpretations of state law. McMillian v. Monroe County, 520 U. S. 781 , 786
(1997); Brockett v. Spokane Arcades, Inc., 472 U. S. 491 , 500, n. 9
(1985). It "rarely reviews a construction of state law agreed upon
by the two lower federal courts." Virginia v. American
Booksellers Assn., Inc., 484 U. S. 383 , 395
(1988). In this case, the two lower courts have both rejected the
Attorney General's narrowing interpretation.

															For another, our precedent warns against accepting as
"authoritative" an Attorney General's interpretation of state law
when "the Attorney General does not bind the state courts or local
law enforcement authorities." Ibid. 941 Under Nebraska law, the Attorney General's interpretative views
do not bind the state courts. State v. Coffman, 213
Neb. 560, 561, 330 N. W. 2d 727, 728 (1983) (Attorney General's
issued opinions, while entitled to "substantial weight" and "to be
respectfully considered," are of "no controlling authority"). Nor
apparently do they bind elected county attorneys, to whom Nebraska
gives an independent authority to initiate criminal prosecutions.
Neb. Rev. Stat. Ann. §§23-1201(1), 28-328(5), 84-205(3) (Supp.
1999); cf. Crandon v. United States, 494 U. S. 152 , 177 (1990)
(SCALIA, J., concurring in judgment) ("[W]e have never thought that
the interpretation of those charged with prosecuting criminal
statutes is entitled to deference").

															Nor can we say that the lower courts used the wrong legal
standard in assessing the Attorney General's interpretation. The
Eighth Circuit recognized its "duty to give [the law] a
construction ... that would avoid constitutional doubts." 192 F.
3d, at 1150. It nonetheless concluded that the Attorney General's
interpretation would "twist the words of the law and give them a
meaning they cannot reasonably bear." Ibid. The Eighth
Circuit is far from alone in rejecting such a narrowing
interpretation. The language in question is based on model
statutory language (though some States omit any further definition
of "partial birth abortion"), which 10 lower federal courts have
considered on the merits. All 10 of those courts (including the
Eighth Circuit) have found the language potentially applicable to
other abortion procedures. See Planned Parenthood of Greater
Iowa, Inc. v. Miller, 195 F.3d
386 (CA8 1999); Little Rock Family Planning Services v. Jegley, 192 F. 3d 794, 797-798 (CA8 1999); Hope
Clinic, 195 F. 3d, at 865-871 (imposing precautionary
injunction to prevent application beyond D&X); id., at
885-889 (Posner, C. J., dissenting); Rhode Island Medical
Soc., 66 F. Supp. 2d, at 309-310; Richmond Medical Center
for Women, 55 942 F. SUpp. 2d, at 471; A Choice for Women, 54 F. Supp. 2d,
at 1155; Causeway Medical Suite, 43 F. Supp. 2d, at 614-615; Planned Parenthood of Central N. J. v. Verniero, 41 F. Supp. 2d 478, 503-504 (NJ 1998); Eubanks v. Stengel, 28 F. Supp. 2d 1024, 1034-1035
(WD Ky. 1998); Planned Parenthood of Southern Ariz., Inc. v. Woods, 982 F. Supp. 2d 1369, 1378 (Ariz. 1997); Kelley, 977 F. Supp. 2d, at 1317; but cf. Richmond
Medical Center v. Gilmore, 144 F.3d
326 , 330-332 (CA4 1998) (Luttig, J., granting stay).

															Regardless, even were we to grant the Attorney General's views
"substantial weight," we still have to reject his interpretation,
for it conflicts with the statutory language discussed supra, at 940. The Attorney General, echoed by the dissents,
tries to overcome that language by relying on other language in the
statute; in particular, the words "partial birth abortion," a term
ordinarily associated with the D&X procedure, and the words
"partially delivers vaginally a living unborn child." Neb. Rev.
Stat. Ann. § 28326(9) (Supp. 1999). But these words cannot help the
Attorney General. They are subject to the statute's further explicit statutory definition, specifying that both terms
include "delivering into the vagina a living unborn child, or a
substantial portion thereof." Ibid. When a statute includes
an explicit definition, we must follow that definition, even if it
varies from that term's ordinary meaning. Meese v. Keene, 481 U.
S. 465 , 484-485 (1987) ("It is axiomatic that the statutory
definition of the term excludes unstated meanings of that term"); Colautti v. Franklin, 439 U. S., at 392-393, n. 10
("As a rule, 'a definition which declares what a term "means" ...
excludes any meaning that is not stated' "); Western Union
Telegraph Co. v. Lenroot, 323 U. S. 490 , 502
(1945); Fox v. Standard Oil Co. of N. J., 294 U. S. 87 ,
95-96 (1935) (Cardozo, J.); see also 2A N. Singer, Sutherland on
Statutes and Statutory Construction § 47.07, p. 152, and n. 10 (5th
ed. 1992) (collecting cases). That is to say, the statute, read "as
a whole," post, at 998 943 (THOMAS, J., dissenting), leads the reader to a definition. That
definition does not include the Attorney General's restriction-"the
child up to the head." Its words, "substantial portion," indicate
the contrary.

															The Attorney General also points to the Nebraska Legislature's
debates, where the term "partial birth abortion" appeared
frequently. But those debates hurt his argument more than they help
it. Nebraska's legislators focused directly upon the meaning of the
word "substantial." One senator asked the bill's sponsor, "[Y]ou
said that as small a portion of the fetus as a foot would
constitute a substantial portion in your opinion. Is that correct?"
The sponsoring senator replied, "Yes, I believe that's correct."
App. 452-453; see also id., at 442-443 (same senator
explaining "substantial" would "indicate that more than a little
bit has been delivered into the vagina," i. e., "[e]nough
that would allow for the procedure to end up with the killing of
the unborn child"); id., at 404 (rejecting amendment to
limit law to D&X). The legislature seems to have wanted to
avoid more limiting language lest it become too easy to evade the
statute's strictures-a motive that JUSTICE THOMAS well explains. Post, at 1001-1003. That goal, however, exacerbates the
problem.

															The Attorney General, again echoed by the dissents, further
argues that the statute "distinguishes between the overall
'abortion procedure' itself and the separate 'procedure' used to
kill the unborn child." Brief for Petitioners 16-18; post, at 991-992 (opinion of THOMAS, J.), 975-976 (opinion of KENNEDY,
J.). Even assuming that the distinction would help the Attorney
General make the D&E/ D&X distinction he seeks, however, we
cannot find any language in the statute that supports it. He wants
us to read "procedure" in the statute's last sentence to mean
"separate procedure," i. e., the killing of the fetus, as
opposed to a whole procedure, i. e., a D&E or D&X
abortion. But the critical word "separate" is missing. And the
same 944 word "procedure," in the same subsection and throughout the
statute, is used to refer to an entire abortion procedure. Neb.
Rev. Stat. Ann. §§ 28-326(9), 28-328(1)-(4) (Supp. 1999); cf. Gustafson v. Alloyd Co., 513 U. S. 561 , 570 (1995)
("[I]dentical words used in different parts of the same act are
intended to have the same meaning" (internal quotation marks
omitted)).

															The dissenters add that the statutory words "partially delivers"
can be read to exclude D&E. Post, at 990-991 (opinion of
THOMAS, J.), 974 (opinion of KENNEDY, J.). They say that
introduction of, say, a limb or both limbs into the vagina does not
involve "delivery." But obstetric textbooks and even dictionaries
routinely use that term to describe any facilitated removal of
tissue from the uterus, not only the removal of an intact fetus. E. g., Obstetrics:

															Normal & Problem Pregnancies, at 388 (describing "delivery"
of fetal membranes, placenta, and umbilical cord in the third stage
of labor); B. Maloy, Medical Dictionary for Lawyers 221 (3d ed.
1960) ("Also, the removal of a [fetal] part such as the placenta");
4 Oxford English Dictionary 422 (2d ed. 1989) (to "deliver" means, inter alia, to "disburden (a women) of the foetus");
Webster's Third New International Dictionary (1993) ("[D]elivery"
means "the expulsion or extraction of a fetus and its membranes").
In any event, the statute itself specifies that it applies both to delivering "an intact unborn child" or "a
substantial portion thereof." The dissents cannot explain how
introduction of a substantial portion of a fetus into the vagina
pursuant to D&X is a "delivery," while introduction pursuant to
D&E is not.

															We are aware that adopting the Attorney General's interpretation
might avoid the constitutional problem discussed in this section.
But we are "without power to adopt a narrowing construction of a
state statute unless such a construction is reasonable and readily
apparent." Boos v. Barry, 485 U. S. 312, 330 (1988); Gooding v. Wilson, 405 U. S. 518 , 520- 945 521 (1972). For the reasons stated, it is not reasonable to
replace the term "substantial portion" with the Attorney General's
phrase "body up to the head." See AlmendarezTorres v. United States, 523 U. S. 224 , 237-239
(1998) (statute must be "genuinely susceptible" to two
interpretations).

															Finally, the law does not require us to certify the state-law
question to the Nebraska Supreme Court. Of course, we lack any
authoritative state-court construction. But "we have never held
that a federal litigant must await a statecourt construction or the
development of an established practice before bringing the federal
suit." City of Lakewood v. Plain Dealer Publishing
Co., 486 U. S.
750 , 770, n. 11 (1988). The Attorney General did not seek a
narrowing interpretation from the Nebraska Supreme Court nor did he
ask the federal courts to certify the interpretive question. See
Brief for State Appellants in Nos. 98-3245 and 98-3300 (CA8); cf. Arizonans for Official English v. Arizona, 520 U. S. 43 (1997). Even if we were inclined to
certify the question now, we cannot do so. Certification of a
question (or abstention) is appropriate only where the statute is
"fairly susceptible" to a narrowing construction, see Houston v. Hill, 482 U. S. 451 , 468-471
(1987). We believe it is not. Moreover, the Nebraska Supreme Court
grants certification only if the certified question is
"determinative of the cause." Neb. Rev. Stat. § 24-219 (1995); see
also Houston v. Hill, supra, at 471 ("It would be
manifestly inappropriate to certify a question in a case where ...
there is no uncertain question of state law whose resolution might
affect the pending federal claim"). Here, it would not be
determinative, in light of the discussion in Part II-A, supra. In sum, using this law some present prosecutors and future
Attorneys General may choose to pursue physicians who use D&E
procedures, the most commonly used method for performing
previability second trimester abortions. All those who perform
abortion procedures using that method must fear prosecution,
conviction, and imprisonment. The 946 result is an undue burden upon a woman's right to make an
abortion decision. We must consequently find the statute
unconstitutional.

															The judgment of the Court of Appeals is

															Affirmed.

															JUSTICE STEVENS, with whom JUSTICE GINSBURG joins,
concurring.

															Although much ink is spilled today describing the gruesome
nature of late-term abortion procedures, that rhetoric does not
provide me a reason to believe that the procedure Nebraska
here claims it seeks to ban is more brutal, more gruesome, or less
respectful of "potential life" than the equally gruesome procedure
Nebraska claims it still allows. JUSTICE GINSBURG and Judge Posner
have, I believe, correctly diagnosed the underlying reason for the
enactment of this legislation-a reason that also explains much of
the Court's rhetoric directed at an objective that extends well
beyond the narrow issue that this case presents. The rhetoric is
almost, but not quite, loud enough to obscure the quiet fact that
during the past 27 years, the central holding of Roe v. Wade, 410 U.
S. 113 (1973), has been endorsed by all but 4 of the 17
Justices who have addressed the issue. That holding-that the word
"liberty" in the Fourteenth Amendment includes a woman's right to
make this difficult and extremely personal decision-makes it
impossible for me to understand how a State has any legitimate
interest in requiring a doctor to follow any procedure other than
the one that he or she reasonably believes will best protect the
woman in her exercise of this constitutional liberty. But one need
not even approach this view today to conclude that Nebraska's law
must fall. For the notion that either of these two equally gruesome
procedures performed at this late stage of gestation is more akin
to infanticide than the other, or that the State furthers any
legitimate interest by banning one but 947 not the other, is simply irrational. See U. S. Const., Amdt.
14.

															JUSTICE O'CONNOR, concurring.

															The issue of abortion is one of the most contentious and
controversial in contemporary American society. It presents
extraordinarily difficult questions that, as the Court recognizes,
involve "virtually irreconcilable points of view." Ante, at
921. The specific question we face today is whether Nebraska's
attempt to proscribe a particular method of abortion, commonly
known as "partial birth abortion," is constitutional. For the
reasons stated in the Court's opinion, I agree that Nebraska's
statute cannot be reconciled with our decision in Planned
Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 (1992), and
is therefore unconstitutional. I write separately to emphasize the
following points.

															First, the Nebraska statute is inconsistent with Casey because it lacks an exception for those instances when the banned
procedure is necessary to preserve the health of the mother. See id., at 879 (plurality opinion). Importantly, Nebraska's own
statutory scheme underscores this constitutional infirmity. As we
held in Casey, prior to viability "the woman has a right to
choose to terminate her pregnancy." Id., at 870. After the
fetus has become viable, States may substantially regulate and even
proscribe abortion, but any such regulation or proscription must
contain an exception for instances "'where it is necessary, in
appropriate medical judgment, for the preservation of the life or
health of the mother.'" Id., at 879 (quoting Roe v. Wade, 410 U.
S. 113 , 165 (1973)). Nebraska has recognized this
constitutional limitation in its separate statute generally
proscribing postviability abortions. See Neb. Rev. Stat. Ann. §
28-329 (Supp. 1999). That statute provides that "[n]o abortion
shall be performed after the time at which, in the sound medical
judgment of the attending physician, the unborn child clearly
appears to have reached viability, except when necessary
to 948 preserve the life or health of the mother." Ibid. (emphasis added). Because even a postviability proscription of
abortion would be invalid absent a health exception, Nebraska's ban
on previability partial birth abortions, under the circumstances
presented here, must include a health exception as well, since the
State's interest in regulating abortions before viability is
"considerably weaker" than after viability. Ante, at 930.
The statute at issue here, however, only excepts those procedures
"necessary to save the life of the mother whose life is endangered
by a physical disorder, physical illness, or physical injury." Neb.
Rev. Stat. Ann. § 28-328(1) (Supp. 1999). This lack of a health
exception necessarily renders the statute unconstitutional.

															Contrary to the assertions of JUSTICE KENNEDY and JusTICE
THOMAS, the need for a health exception does not arise from "the
individual views of Dr. Carhart and his supporters." Post, at 969 (KENNEDY, J., dissenting); see also post, at
1012-1013 (THOMAS, J., dissenting). Rather, as the majority
explains, where, as here, "a significant body of medical opinion
believes a procedure may bring with it greater safety for some
patients and explains the medical reasons supporting that view," ante, at 937, then Nebraska cannot say that the procedure
will not, in some circumstances, be "necessary to preserve the life
or health of the mother." Accordingly, our precedent requires that
the statute include a health exception.

															Second, Nebraska's statute is unconstitutional on the
alternative and independent ground that it imposes an undue burden
on a woman's right to choose to terminate her pregnancy before
viability. Nebraska's ban covers not just the dilation and
extraction (D&X) procedure, but also the dilation and
evacuation (D&E) procedure, "the most commonly used method for
performing previability second trimester abortions." Ante, at 945. The statute defines the banned procedure as "deliberately
and intentionally delivering into the vagina a living unborn child, or a substantial portion 949 thereof, for the purpose of performing a procedure that
the person performing such procedure knows will kill the unborn
child and does kill the unborn child." Neb. Rev. Stat. Ann. §
28-326(9) (Supp. 1999) (emphasis added). As the Court explains, the
medical evidence establishes that the D&E procedure is included
in this definition. Thus, it is not possible to interpret the
statute's language as applying only to the D&X procedure.
Moreover, it is significant that both the District Court and the
Court of Appeals interpreted the statute as prohibiting abortions
performed using the D&E method as well as the D&X method.
See 192 F.3d
1142 , 1150 (CA8 1999); 11 F. Supp. 2d 1099, 1127-1131
(Neb. 1998). We have stated on several occasions that we ordinarily
defer to the construction of a state statute given it by the lower
federal courts unless such a construction amounts to plain error.
See, e. g., Bishop v. Wood, 426 U. S. 341 , 346 (1976)
("[T]his Court has accepted the interpretation of state law in
which the District Court and the Court of Appeals have concurred
even if an examination of the state-law issue without such guidance
might have justified a different conclusion"); The Tungus v. Skovgaard, 358
U. S. 588 , 596 (1959). Such deference is not unique to the
abortion context, but applies generally to state statutes
addressing all areas of the law. See, e. g., UNUM Life Ins. Co.
of America v. Ward, 526 U. S. 358 , 368 (1999)
("notice-prejudice" rule in state insurance law); Brockett v. Spokane Arcades, Inc., 472 U. S. 491 , 499 (1985)
(moral nuisance law); Runyon v. McCrary, 427 U. S. 160 , 181 (1976)
(statute of limitations for personal injury actions); Bishop v. Wood, supra, at 346, n. 10 (city employment ordinance).
Given this construction, the statute is impermissible. Indeed,
Nebraska conceded at oral argument that "the State could not
prohibit the D&E procedure." Tr. of Oral Arg. 10. By
proscribing the most commonly used method for previability second
trimester abortions, see ante, at 924, the statute creates a
"substantial obstacle to a woman seeking an abortion," Casey,
supra, at 884, and therefore imposes 950 an undue burden on a woman's right to terminate her pregnancy
prior to viability.

															It is important to note that, unlike Nebraska, some other States
have enacted statutes more narrowly tailored to proscribing the
D&X procedure alone. Some of those statutes have done so by
specifically excluding from their coverage the most common methods
of abortion, such as the D&E and vacuum aspiration procedures.
For example, the Kansas statute states that its ban does not apply
to the "(A) [s]uction curettage abortion procedure; (B) suction
aspiration abortion procedure; or (C) dilation and
evacuation abortion procedure involving dismemberment of the fetus
prior to removal from the body of the pregnant woman." Kan. Stat.
Ann. § 656721(b)(2) (Supp. 1998). The Utah statute similarly
provides that its prohibition "does not include the dilation and
evacuation procedure involving dismemberment prior to removal, the
suction curettage procedure, or the suction aspiration procedure
for abortion." Utah Code Ann. § 76-7310.5(1)(a) (1999). Likewise,
the Montana statute defines the banned procedure as one in which
"(A) the living fetus is removed intact from the uterus until only
the head remains in the uterus; (B) all or a part of the
intracranial contents of the fetus are evacuated; (C) the
head of the fetus is compressed; and (D) following fetal demise,
the fetus is removed from the birth canal." Mont. Code Ann. §
50-20401(3)(c)(ii) (Supp. 1999). By restricting their prohibitions
to the D&X procedure exclusively, the Kansas, Utah, and Montana
statutes avoid a principal defect of the Nebraska law.

															If Nebraska's statute limited its application to the D&X
procedure and included an exception for the life and health of the
mother, the question presented would be quite different from the
one we face today. As we held in Casey, an abortion
regulation constitutes an undue burden if it "has the purpose or
effect of placing a substantial obstacle in the path of a woman
seeking an abortion of a nonviable fetus." 951 505 U. S., at 877. If there were adequate alternative methods
for a woman safely to obtain an abortion before viability, it is
unlikely that prohibiting the D&X procedure alone would "amount
in practical terms to a substantial obstacle to a woman seeking an
abortion." Id., at 884. Thus, a ban on partial birth
abortion that only proscribed the D&X method of abortion and
that included an exception to preserve the life and health of the
mother would be constitutional in my view.

															Nebraska's statute, however, does not meet these criteria.

															It contains no exception for when the procedure, in appropriate
medical judgment, is necessary to preserve the health of the
mother; and it proscribes not only the D&X procedure but also
the D&E procedure, the most commonly used method for
previability second trimester abortions, thus making it an undue
burden on a woman's right to terminate her pregnancy. For these
reasons, I agree with the Court that Nebraska's law is
unconstitutional.

															JUSTICE GINSBURG, with whom JUSTICE STEVENS joins,
concurring.

															I write separately only to stress that amidst all the emotional
uproar caused by an abortion case, we should not lose sight of the
character of Nebraska's "partial birth abortion" law. As the Court
observes, this law does not save any fetus from destruction, for it
targets only "a method of performing abortion." Ante, at 930. Nor does the statute seek to protect the lives or health of
pregnant women. Moreover, as JUSTICE STEVENS points out, ante, at 946 (concurring opinion), the most common method of
performing previability second trimester abortions is no less
distressing or susceptible to gruesome description. Seventh Circuit
Chief Judge Posner correspondingly observed, regarding similar bans
in Wisconsin and Illinois, that the law prohibits the D&X
procedure "not because the procedure kills the fetus, not because
it risks worse complications for the woman 952 than alternative procedures would do, not because it is a
crueler or more painful or more disgusting method of terminating a
pregnancy." Hope Clinic v. Ryan, 195 F.3d
857 , 881 (CA7 1999) (dissenting opinion). Rather, Chief
Judge Posner commented, the law prohibits the procedure because the
state legislators seek to chip away at the private choice shielded
by Roe v. Wade, 410 U. S. 113 (1973),
even as modified by Planned Parenthood of Southeastern Pa. v. Casey, 505
U. S. 833 (1992). 195 F. 3d, at 880-882.

															A state regulation that "has the purpose or effect of placing a
substantial obstacle in the path of a woman seeking an abortion of
a nonviable fetus" violates the Constitution. Casey, 505 U.
S., at 877 (plurality opinion). Such an obstacle exists if the
State stops a woman from choosing the procedure her doctor
"reasonably believes will best protect the woman in [the] exercise
of [her] constitutional liberty." Ante, at 946 (STEVENS, J.,
concurring); see Casey, 505 U. S., at 877 ("means chosen by
the State to further the interest in potential life must be
calculated to inform the woman's free choice, not hinder it").
Again as stated by Chief Judge Posner, "if a statute burdens
constitutional rights and all that can be said on its behalf is
that it is the vehicle that legislators have chosen for expressing
their hostility to those rights, the burden is undue." Hope
Clinic, 195 F. 3d, at 881.

															CHIEF JUSTICE REHNQUIST, dissenting.

															I did not join the joint opinion in Planned Parenthood of
Southeastern Pa. v. Casey, 505 U. S. 833 (1992), and
continue to believe that case is wrongly decided. Despite my
disagreement with the opinion, under the rule laid down in Marks v. United States, 430 U. S. 188 , 193
(1977), the Casey joint opinion represents the holding of
the Court in that case. I believe JUSTICE KENNEDY and JUSTICE
THOMAS have correctly applied Casey's principles and join
their dissenting opinions. 953 JUSTICE SCALIA, dissenting.

															I am optimistic enough to believe that, one day, Stenberg v. Carhart will be assigned its rightful place in the
history of this Court's jurisprudence beside Korematsu and Dred Scott. The method of killing a human child-one cannot
even accurately sayan entirely unborn human child-proscribed by
this statute is so horrible that the most clinical description of
it evokes a shudder of revulsion. And the Court must know (as most
state legislatures banning this procedure have concluded) that
demanding a "health exception"-which requires the abortionist to
assure himself that, in his expert medical judgment, this method
is, in the case at hand, marginally safer than others (how can one
prove the contrary beyond a reasonable doubt?)-is to give
live-birth abortion free rein. The notion that the Constitution of
the United States, designed, among other things, "to establish
Justice, insure domestic Tranquility, ... and secure the Blessings
of Liberty to ourselves and our Posterity," prohibits the States
from simply banning this visibly brutal means of eliminating our
half-born posterity is quite simply absurd.

															Even so, I had not intended to write separately here until the
focus of the other separate writings (including the one I have
joined) gave me cause to fear that this case might be taken to
stand for an error different from the one that it actually
exemplifies. Because of the Court's practice of publishing dissents
in the order of the seniority of their authors, this writing will
appear in the United States Reports before those others, but the
reader will not comprehend what follows unless he reads them
first.

															***

															The two lengthy dissents in this case have, appropriately
enough, set out to establish that to day's result does not follow
from this Court's most recent pronouncement on the matter of
abortion, Planned Parenthood of Southeastern Pa. v. Casey, 505 U.
S. 833 (1992). It would be unfortunate, how- 954 ever, if those who disagree with the result were induced to
regard it as merely a regrettable misapplication of Casey. It is not that, but is Casey's logical and entirely
predictable consequence. To be sure, the Court's construction of
this statute so as to make it include procedures other than
livebirth abortion involves not only a disregard of fair meaning,
but an abandonment of the principle that even ambiguous statutes
should be interpreted in such fashion as to render them valid
rather than void. Casey does not permit that jurisprudential novelty-which must be chalked up to the Court's
inclination to bend the rules when any effort to limit abortion, or
even to speak in opposition to abortion, is at issue. It is of a
piece, in other words, with Hill v. Colorado, ante, p. 703, also decided today.

															But the Court gives a second and independent reason for
invalidating this humane (not to say antibarbarian) law: That it
fails to allow an exception for the situation in which the
abortionist believes that this live-birth method of destroying the
child might be safer for the woman. (As pointed out by JUSTICE
THOMAS, and elaborated upon by JUSTICE KENNEDY, there is no good
reason to believe this is ever the case, but-who knows?-it sometime might be.)

															I have joined JUSTICE THOMAS'S dissent because I agree that to
day's decision is an "unprecedented expansio[n]" of our prior
cases, post, at 1012, "is not mandated" by Casey's "undue-burden" test, post, at 1010, and can even be called
(though this pushes me to the limit of my belief) "obviously
irreconcilable with Casey's explication of what its
undueburden standard requires," post, at 983. But I never
put much stock in Casey's explication of the inexplicable.
In the last analysis, my judgment that Casey does not
support today's tragic result can be traced to the fact that what I
consider to be an "undue burden" is different from what the
majority considers to be an "undue burden"-a conclusion that cannot
be demonstrated true or false by factual inquiry or legal
reasoning. It is a value judgment, dependent upon how much one
respects (or believes society ought to respect) 955 the life of a partially delivered fetus, and how much one
respects (or believes society ought to respect) the freedom of the
woman who gave it life to kill it. Evidently, the five Justices in
to day's majority value the former less, or the latter more, (or
both), than the four of us in dissent. Case closed. There is no
cause for anyone who believes in Casey to feel betrayed by
this outcome. It has been arrived at by precisely the process Casey promised-a democratic vote by nine lawyers, not on the
question whether the text of the Constitution has anything to say
about this subject (it obviously does not); nor even on the
question (also appropriate for lawyers) whether the legal
traditions of the American people would have sustained such a
limitation upon abortion (they obviously would); but upon the pure
policy question whether this limitation upon abortion is "undue"-i. e., goes too far.

															In my dissent in Casey, I wrote that the "undue burden"
test made law by the joint opinion created a standard that was "as
doubtful in application as it is unprincipled in origin," Casey, 505 U. S., at 985; "hopelessly unworkable in
practice," id., at 986; "ultimately standardless," id., at 987. Today's decision is the proof. As long as we
are debating this issue of necessity for a health-of-the-mother
exception on the basis of Casey, it is really quite
impossible for us dissenters to contend that the majority is wrong on the lawany more than it could be said that one is wrong in law to support or oppose the death penalty, or to
support or oppose mandatory minimum sentences. The most that we can
honestly say is that we disagree with the majority on their
policy-judgment-couched-as-Iaw. And those who believe that a 5-to-4
vote on a policy matter by unelected lawyers should not overcome
the judgment of 30 state legislatures have a problem, not with the application of Casey, but with its existence.
Casey must be overruled.

															While I am in an I-told-you-so mood, I must recall my
bemusement, in Casey, at the majority opinion's expressed
be- 956 lief that Roe v. Wade, 410 U. S. 133 (1973), had
"call[ed] the contending sides of a national controversy to end
their national division by accepting a common mandate rooted in the
Constitution," Casey, 505 U. S., at 867, and that the
decision in Casey would ratify that happy truce. It seemed
to me, quite to the contrary, that "Roe fanned into life an
issue that has inflamed our national politics in general, and has
obscured with its smoke the selection of Justices to this Court in
particular, ever since"; and that, "by keeping us in the
abortion-umpiring business, it is the perpetuation of that
disruption, rather than of any Pax Roeana, that the Court's
new majority decrees." Id., at 995-996. Today's decision,
that the Constitution of the United States prevents the prohibition
of a horrible mode of abortion, will be greeted by a fire storm of
criticism-as well it should. I cannot understand why those who acknowledge that, in the opening words of JUSTICE O'CONNOR'S
concurrence, "[t]he issue of abortion is one of the most
contentious and controversial in contemporary American society," ante, at 947, persist in the belief that this Court, armed
with neither constitutional text nor accepted tradition, can
resolve that contention and controversy rather than be consumed by
it. If only for the sake of its own preservation, the Court should
return this matter to the people-where the Constitution, by its
silence on the subject, left it-and let them decide, State
by State, whether this practice should be allowed. Casey must be overruled.

															JUSTICE KENNEDY, with whom THE CHIEF JUSTICE joins,
dissenting.

															For close to two decades after Roe v. Wade, 410 U. S. 113 (1973), the Court gave but slight weight to the interests of the
separate States when their legislatures sought to address
persisting concerns raised by the existence of a woman's right to
elect an abortion in defined circumstances. When the Court
reaffirmed the essential holding of Roe, a central premise
was that the States retain a critical and legitimate 957 role in legislating on the subject of abortion, as limited by
the woman's right the Court restated and again guaranteed. Planned Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 (1992). The political processes of the State are not to be
foreclosed from enacting laws to promote the life of the unborn and
to ensure respect for all human life and its potential. Id., at 871 (plurality opinion). The State's constitutional authority is
a vital means for citizens to address these grave and serious
issues, as they must if we are to progress in knowledge and
understanding and in the attainment of some degree of
consensus.

															The Court's decision today, in my submission, repudiates this
understanding by invalidating a statute advancing critical state
interests, even though the law denies no woman the right to choose
an abortion and places no undue burden upon the right. The
legislation is well within the State's competence to enact. Having
concluded Nebraska's law survives the scrutiny dictated by a proper
understanding of Casey, I dissent from the judgment
invalidating it.

															I

															The Court's failure to accord any weight to Nebraska's interest
in prohibiting partial birth abortion is erroneous and undermines
its discussion and holding. The Court's approach in this regard is
revealed by its description of the abortion methods at issue, which
the Court is correct to describe as "clinically cold or callous." Ante, at 923. The majority views the procedures from the
perspective of the abortionist, rather than from the perspective of
a society shocked when confronted with a new method of ending human
life. Words invoked by the majority, such as "transcervical
procedures," "[o]smotic dilators," "instrumental disarticulation,"
and "paracervical block," may be accurate and are to some extent
necessary, ante, at 924-925; but for citizens who seek to
know why laws on this subject have been enacted across the Nation,
the words are insufficient. Repeated references 958 to sources understandable only to a trained physician may
obscure matters for persons not trained in medical terminology.
Thus it seems necessary at the outset to set forth what may happen
during an abortion.

															The person challenging Nebraska's law is Dr. Leroy Carhart, a
physician who received his medical degree from Hahnemann Hospital
and University in 1973. App. 29. Dr. Carhart performs the
procedures in a clinic in Nebraska, id., at 30, and will
also travel to Ohio to perform abortions there, id., at 86.
Dr. Carhart has no specialty certifications in a field related to
childbirth or abortion and lacks admitting privileges at any
hospital. Id., at 82, 83. He performs abortions throughout
pregnancy, including when he is unsure whether the fetus is viable. Id., at 116. In contrast to the physicians who provided
expert testimony in this case (who are board certified instructors
at leading medical education institutions and members of the
American Board of Obstetricians and Gynecologists), Dr. Carhart
performs the partial birth abortion procedure (D&X) that
Nebraska seeks to ban. He also performs the other method of
abortion at issue in the case, the D&E.

															As described by Dr. Carhart, the D&E procedure requires the
abortionist to use instruments to grasp a portion (such as a foot
or hand) of a developed and living fetus and drag the grasped
portion out of the uterus into the vagina. Id., at 61. Dr.
Carhart uses the traction created by the opening between the uterus
and vagina to dismember the fetus, tearing the grasped portion away
from the remainder of the body. Ibid. The traction between
the uterus and vagina is essential to the procedure because
attempting to abort a fetus without using that traction is
described by Dr. Carhart as "pulling the eat's tail" or "drag[ging]
a string across the floor, you'll just keep dragging it. It's not
until something grabs the other end that you are going to develop
traction." Id., at 62. The fetus, in many cases, dies just
as a human adult or child would: It bleeds to death as it is torn
limb from 959 limb. Id., at 63. The fetus can be alive at the beginning
of the dismemberment process and can survive for a time while its
limbs are being torn off. Dr. Carhart agreed that "[w]hen you pull
out a piece of the fetus, let's say, an arm or a leg and remove
that, at the time just prior to removal of the portion of the
fetus, ... the fetus [is] alive." Id., at 62. Dr. Carhart
has observed fetal heartbeat via ultrasound with "extensive parts
of the fetus removed," id., at 64, and testified that mere
dismemberment of a limb does not always cause death because he
knows of a physician who removed the arm of a fetus only to have
the fetus go on to be born "as a living child with one arm." Id., at 63. At the conclusion of a D&E abortion no
intact fetus remains. In Dr. Carhart's words, the abortionist is
left with "a tray full of pieces." Id., at 125.

															The other procedure implicated today is called "partial birth
abortion" or the D&X. The D&X can be used, as a general
matter, after 19 weeks' gestation because the fetus has become so
developed that it may survive intact partial delivery from the
uterus into the vagina. Id., at 61. In the D&X, the
abortionist initiates the woman's natural delivery process by
causing the cervix of the woman to be dilated, sometimes over a
sequence of days. Id., at 492. The fetus' arms and legs are
delivered outside the uterus while the fetus is alive; witnesses to
the procedure report seeing the body of the fetus moving outside
the woman's body. Brief for Petitioners 4. At this point, the
abortion procedure has the appearance of a live birth. As stated by
one group of physicians, "[a]s the physician manually performs
breech extraction of the body of a live fetus, excepting the head,
she continues in the apparent role of an obstetrician delivering a
child." Brief for Association of American Physicians and Surgeons
et al. as Amici Curiae 27. With only the head of the fetus
remaining in utero, the abortionist tears open the skull. According
to Dr. Martin Haskell, a leading proponent of the procedure, the
appropriate instrument to be used at 960 this stage of the abortion is a pair of scissors. M. Haskell,
Dilation and Extraction for Late Second Trimester Abortion (1992),
in 139 Congo Rec. 8605 (1993). Witnesses report observing the
portion of the fetus outside the woman react to the skull
penetration. Brief for Petitioners 4. The abortionist then inserts
a suction tube and vacuums out the developing brain and other
matter found within the skull. The process of making the size of
the fetus' head smaller is given the clinically neutral term
"reduction procedure." 11 F. Supp. 2d 1099, 1106 (Neb. 1998). Brain
death does not occur until after the skull invasion, and, according
to Dr. Carhart, the heart of the fetus may continue to beat for
minutes after the contents of the skull are vacuumed out. App. 58.
The abortionist next completes the delivery of a dead fetus, intact
except for the damage to the head and the missing contents of the
skull.

															Of the two described procedures, Nebraska seeks only to ban the
D&X. In light of the description of the D&X procedure, it
should go without saying that Nebraska's ban on partial birth
abortion furthers purposes States are entitled to pursue. Dr.
Carhart nevertheless maintains the State has no legitimate interest
in forbidding the D&X. As he interprets the controlling cases
in this Court, the only two interests the State may advance through
regulation of abortion are in the health of the woman who is
considering the procedure and in the life of the fetus she carries.
Brief for Respondent 45. The Court, as I read its opinion, accedes
to his views, misunderstanding Casey and the authorities it
confirmed. Casey held that cases decided in the wake of Roe v. Wade, 410
U. S. 113 (1973), had "given [state interests] too little
acknowledgment and implementation." 505 U. S., at 871 (plurality
opinion). The decision turned aside any contention that a person
has the "right to decide whether to have an abortion without
'interference from the State,'" id., at 875, and rejected a
strict scrutiny standard of review as "in- 961 compatible with the recognition that there is a substantial
state interest in potential life throughout pregnancy." Id., at 876. "The very notion that the State has a substantial interest
in potential life leads to the conclusion that not all regulations
must be deemed unwarranted." Ibid. We held it was
inappropriate for the Judicial Branch to provide an exhaustive list
of state interests implicated by abortion. Id., at 877. Casey is premised on the States having an important
constitutional role in defining their interests in the abortion
debate. It is only with this principle in mind that Nebraska's
interests can be given proper weight. The State's brief describes
its interests as including concern for the life of the unborn and
"for the partially-born," in preserving the integrity of the
medical profession, and in "erecting a barrier to infanticide."
Brief for Petitioners 48-49. A review of Casey demonstrates
the legitimacy of these policies. The Court should say so.

															States may take sides in the abortion debate and come

															down on the side of life, even life in the unborn: "Even in the earliest stages of pregnancy, the State may enact
rules and regulations designed to encourage [a woman] to know that
there are philosophic and social arguments of great weight that can
be brought to bear in favor of continuing the pregnancy to full
term and that there are procedures and institutions to allow
adoption of unwanted children as well as a certain degree of state
assistance if the mother chooses to raise the child herself." 505
U. S., at 872 (plurality opinion). States also have an interest in forbidding medical procedures
which, in the State's reasonable determination, might cause the
medical profession or society as a whole to become insensitive,
even disdainful, to life, including life in the human fetus.
Abortion, Casey held, has consequences beyond the woman and
her fetus. The States' interests in reg- 962 ulating are of concomitant extension. Casey recognized
that abortion is "fraught with consequences for ... the persons who
perform and assist in the procedure [and for] society which must
confront the knowledge that these procedures exist, procedures some
deem nothing short of an act of violence against innocent human
life." Id., at 852 (majority opinion).

															A State may take measures to ensure the medical profession and
its members are viewed as healers, sustained by a compassionate and
rigorous ethic and cognizant of the dignity and value of human
life, even life which cannot survive without the assistance of
others. Ibid.; Washington v. Glucksberg, 521 U. S. 702 , 730-734
(1997). Casey demonstrates that the interests asserted by the
State are legitimate and recognized by law. It is argued, however,
that a ban on the D&X does not further these interests. This is
because, the reasoning continues, the D&E method, which
Nebraska claims to be beyond its intent to regulate, can still be
used to abort a fetus and is no less dehumanizing than the D&X
method. While not adopting the argument in express terms, the Court
indicates tacit approval of it by refusing to reject it in a
forthright manner. Rendering express what is only implicit in the
majority opinion, JUSTICE STEVENS and JUSTICE GINSBURG are
forthright in declaring that the two procedures are
indistinguishable and that Nebraska has acted both irrationally and
without a proper purpose in enacting the law. The issue is not
whether members of the judiciary can see a difference between the
two procedures. It is whether Nebraska can. The Court's refusal to
recognize Nebraska's right to declare a moral difference between
the procedures is a dispiriting disclosure of the illogic and
illegitimacy of the Court's approach to the entire case.

															Nebraska was entitled to find the existence of a consequential
moral difference between the procedures. We are referred to
substantial medical authority that D&X perverts 963 the natural birth process to a greater degree than D&E,
commandeering the live birth process until the skull is pierced.
American Medical Association (AMA) publications describe the
D&X abortion method as "ethically wrong." AMA Board of Trustees
Factsheet on HR 1122 (June 1997), in App. to Brief for Association
of American Physicians and Surgeons et al. as Amici Curiae 1
(AMA Factsheet). The D&X differs from the D&E because in
the D&X the fetus is "killed outside of the womb" where
the fetus has "an autonomy which separates it from the right of the
woman to choose treatments for her own body." Ibid.; see
also App. 639-640; Brief for Association of American Physicians and
Surgeons et al. as Amici Curiae 27 ("Intact D&X is
aberrant and troubling because the technique confuses the disparate
role of a physician in childbirth and abortion in such a way as to
blur the medical, legal, and ethical line between infanticide and
abortion"). Witnesses to the procedure relate that the fingers and
feet of the fetus are moving prior to the piercing of the skull;
when the scissors are inserted in the back of the head, the fetus'
body, wholly outside the woman's body and alive, reacts as though
startled and goes limp. D&X's stronger resemblance to
infanticide means Nebraska could conclude the procedure presents a
greater risk of disrespect for life and a consequent greater risk
to the profession and society, which depend for their sustenance
upon reciprocal recognition of dignity and respect. The Court is
without authority to second-guess this conclusion.

															Those who oppose abortion would agree, indeed would insist, that
both procedures are subject to the most severe moral condemnation,
condemnation reserved for the most repulsive human conduct. This is
not inconsistent, however, with the further proposition that as an
ethical and moral matter D&X is distinct from D&E and is a
more serious concern for medical ethics and the morality of the
larger society the medical profession must serve. Nebraska must
obey the legal regime which has declared the right of the woman
to 964 have an abortion before viability. Yet it retains its power to
adopt regulations which do not impose an undue burden on the
woman's right. By its regulation, Nebraska instructs all
participants in the abortion process, including the mother, of its
moral judgment that all life, including the life of the unborn, is
to be respected. The participants, Nebraska has determined, cannot
be indifferent to the procedure used and must refrain from using
the natural delivery process to kill the fetus. The differentiation
between the procedures is itself a moral statement, serving to
promote respect for human life; and if the woman and her physician
in contemplating the moral consequences of the prohibited procedure
conclude that grave moral consequences pertain to the permitted
abortion process as well, the choice to elect or not to elect
abortion is more informed; and the policy of promoting respect for
life is advanced.

															It ill-serves the Court, its institutional position, and the
constitutional sources it seeks to invoke to refuse to issue a
forthright affirmation of Nebraska's right to declare that critical
moral differences exist between the two procedures. The natural
birth process has been appropriated; yet the Court refuses to hear
the State's voice in defining its interests in its law. The Court's
holding contradicts Casey's assurance that the State's
constitutional position in the realm of promoting respect for life
is more than marginal.

															II

															Demonstrating a further and basic misunderstanding of Casey, the Court holds the ban on the D&X procedure
fails because it does not include an exception permitting an
abortionist to perform a D&X whenever he believes it will best
preserve the health of the woman. Casting aside the views of
distinguished physicians and the statements of leading medical
organizations, the Court awards each physician a veto power over
the State's judgment that the procedures should not be performed.
Dr. Carhart has made the medical 965 judgment to use the D&X procedure in every case, regardless
of indications, after 15 weeks' gestation. 11 F. Supp. 2d, at 1105.
Requiring Nebraska to defer to Dr. Carhart's judgment is no
different from forbidding Nebraska from enacting a ban at all; for
it is now Dr. Leroy Carhart who sets abortion policy for the State
of Nebraska, not the legislature or the people. Casey does
not give precedence to the views of a single physician or a group
of physicians regarding the relative safety of a particular
procedure.

															I am in full agreement with JUSTICE THOMAS that the appropriate Casey inquiry is not, as the Court would have it, whether
the State is preventing an abortionist from doing something that,
in his medical judgment, he believes to be the most appropriate
course of treatment. Post, at 1009 1013. Casey addressed the question "whether the State can resolve ...
philosophic questions [about abortion] in such a definitive way
that a woman lacks all choice in the matter." 505 U. S., at 850. We
decided the issue against the State, holding that a woman cannot be
deprived of the opportunity to make reproductive decisions. Id., at 860. Casey made it quite evident, however,
that the State has substantial concerns for childbirth and the life
of the unborn and may enact laws "which in no real sense depriv[e]
women of the ultimate decision." Id., at 875 (plurality
opinion). Laws having the "purpose or effect of placing a
substantial obstacle in the path of a woman seeking an abortion of
a nonviable fetus" are prohibited. Id., at 877. Nebraska's
law does not have this purpose or effect.

															The holding of Casey, allowing a woman to elect abortion
in defined circumstances, is not in question here. Nebraska,
however, was entitled to conclude that its ban, while advancing
important interests regarding the sanctity of life, deprived no
woman of a safe abortion and therefore did not impose a substantial
obstacle on the rights of any woman. The American College of
Obstetricians and Gynecologists (ACOG) "could identify no
circumstances under which [D&X] 966 would be the only option to save the life or preserve the health
of the woman." App. 600-601. The AMA agrees, stating the "AMA's
expert panel, which included an ACOG representative, could not find
'any' identified circumstance where it was 'the only appropriate
alternative.'" AMA Factsheet 1. The Court's conclusion that the
D&X is the safest method requires it to replace the words "may
be" with the word "is" in the following sentence from ACOG's
position statement: "An intact D&X, however, may be the best or
most appropriate procedure in a particular circumstance."
App.600-601.

															No studies support the contention that the D&X abortion
method is safer than other abortion methods. Brief for Respondent
36, n. 41. Leading proponents of the procedure acknowledge that the
D&X has "disadvantages" versus other methods because it
requires a high degree of surgical skill to pierce the skull with a
sharp instrument in a blind procedure. Haskell, 139 Congo Rec. 8605
(1993). Other doctors point to complications that may arise from
the D&X. Brief for American Physicians and Surgeons et al. as Amici Cu riae 21-23; App. 186. A leading physician, Frank
Boehm, M. D., who has performed and supervised abortions as
director of the Fetal Intensive Care Unit and the Maternal/Fetal
Medicine Division at Vanderbilt University Hospital, has refused to
support use of the D&X, both because no medical need for the
procedure exists and because of ethical concerns. Id., at
636, 639-640, 656-657. Dr. Boehm, a fellow of ACOG, id., at
565, supports abortion rights and has provided sworn testimony in
opposition to previous state attempts to regulate abortion. Id., at 608-614.

															The Court cannot conclude the D&X is part of standard
medical practice. It is telling that no expert called by Dr.
Carhart, and no expert testifying in favor of the procedure, had in
fact performed a partial birth abortion in his or her medical
practice. E. g., id., at 308 (testimony of Dr. Phillip
Stubblefield). In this respect their opinions were 967 courtroom conversions of uncertain reliability. Litigation in
other jurisdictions establishes that physicians do not adopt the
D&X procedure as part of standard medical practice.

															Substantial evidence supports Nebraska's conclusion that its law
denies no woman a safe abortion. The most to be said for the
D&X is it may present an unquantified lower risk of
complication for a particular patient but that other proven safe
procedures remain available even for this patient. Under these
circumstances, the Court is wrong to limit its inquiry to the
relative physical safety of the two procedures, with the slightest
potential difference requiring the invalidation of the law. As
JUSTICE O'CONNOR explained in an earlier case, the State may
regulate based on matters beyond "what various medical
organizations have to say about the physical safety of a
particular procedure." Akron v. Akron Center for
Reproductive Health, Inc., 462 U. S. 416, 467 (1983)
(dissenting opinion). Where the difference in physical safety is,
at best, marginal, the State may take into account the grave moral
issues presented by a new abortion method. See Casey, 505 U.
S., at 880 (requiring a regulation to impose a "significant threat
to the life or health of a woman" before its application would
impose an undue burden (internal quotation marks omitted)). Dr.
Carhart does not decide to use the D&X based on a conclusion
that it is best for a particular woman. Unsubstantiated and
gen- 968 eralized health differences which are, at best, marginal, do not
amount to a substantial obstacle to the abortion right. Id., at 874, 876 (plurality opinion). It is also important to recognize
that the D&X is effective only when the fetus is close to
viable or, in fact, viable; thus the State is regulating the
process at the point where its interest in life is nearing its
peak.

															Courts are ill-equipped to evaluate the relative worth of
particular surgical procedures. The legislatures of the several
States have superior factfinding capabilities in this regard. In an
earlier case, JUSTICE O'CONNOR had explained that the general rule
extends to abortion cases, writing that the Court is not suited to
be "the Nation's ex officio medical board with powers to
approve or disapprove medical and operative practices and standards
throughout the United States." 462 U. S., at 456 (dissenting
opinion) (internal quotation marks omitted). "Irrespective of the
difficulty of the task, legislatures, with their superior
factfinding capabilities, are certainly better able to make the
necessary judgments than are courts." Id., at 456, n. 4.
Nebraska's judgment here must stand.

															In deferring to the physician's judgment, the Court turns back
to cases decided in the wake of Roe, cases which gave a
physician's treatment decisions controlling weight. Before it was
repudiated by Casey, the approach of deferring to physicians
had reached its apex in Akron, supra, where the Court held
an informed consent requirement was unconstitutional. The law
challenged in Akron required the abortionist to inform the
woman of the status of her pregnancy, the development of her fetus,
the date of possible viability, the physical and emotional
complications that may result from an abortion, and the
availability of agencies to provide assistance and information. Id., at 442. The physician was also required to advise the
woman of the risks associated with the abortion technique to be
employed and other information. Ibid. The law was
invalidated based on the physi- 969 cian's right to practice medicine in the way he or she saw fit;
for, according to the Akron Court, "[i]t remains primarily
the responsibility of the physician to ensure that appropriate
information is conveyed to his patient, depending on her particular
circumstances." Id., at 443. Dispositive for the Court was
that the law was an "intrusion upon the discretion of the pregnant
woman's physician." Id., at 445. The physician was placed in
an "undesired and uncomfortable straitjacket." Ibid. (internal quotation marks omitted). The Court's decision today
echoes the Akron Court's deference to a physician's right to
practice medicine in the way he or she sees fit.

															The Court, of course, does not wish to cite Akron; yet
the Court's holding is indistinguishable from the reasoning in Akron that Casey repudiated. No doubt exists that
today's holding is based on a physician-first view which finds its
primary support in that now-discredited case. Rather than exalting
the right of a physician to practice medicine with unfettered
discretion, Casey recognized: "Whatever constitutional
status the doctor-patient relation may have as a general matter, in
the present context it is derivative of the woman's position." 505
U. S., at 884 (joint opinion of O'CONNOR, KENNEDY, and SOUTER,
JJ.). Casey discussed the informed consent requirement
struck down in Akron and held Akron was wrong. The
doctor-patient relation was only "entitled to the same solicitude
it receives in other contexts." 505 U. S., at 884. The standard of
medical practice cannot depend on the individual views of Dr.
Carhart and his supporters. The question here is whether there was
substantial and objective medical evidence to demonstrate the State
had considerable support for its conclusion that the ban created a
substantial risk to no woman's health. Casey recognized the
point, holding the physician's ability to practice medicine was
"subject to reasonable ... regulation by the State" and would
receive the "same solicitude it receives in other contexts." Ibid. In other contexts, the State is enti- 970 tIed to make judgments where high medical authority is in
disagreement.

															The Court fails to acknowledge substantial authority allowing
the State to take sides in a medical debate, even when fundamental
liberty interests are at stake and even when leading members of the
profession disagree with the conclusions drawn by the legislature.
In Kansas v. Hendricks, 521 U. S. 346 (1997), we
held that disagreements among medical professionals "do not tie the
State's hands in setting the bounds of ... laws. In fact, it is
precisely where such disagreement exists that legislatures have
been afforded the widest latitude." Id., at 360, n. 3.
Instead, courts must exercise caution (rather than require
deference to the physician's treatment decision) when medical
uncertainty is present. Ibid. ("[W]hen a legislature
'undertakes to act in areas fraught with medical and scientific
uncertainties, legislative options must be especially broad and
courts should be cautious not to rewrite legislation''') (quoting Jones v. United States, 463 U. S. 354 , 370
(1983)); see also Collins v. Texas, 223 U. S. 288 , 297-298
(1912) (Holmes, J.) (declaring the "right of the state to adopt a
policy even upon medical matters concerning which there is
difference of opinion and dispute"); Lambert v. Yellowley, 272
U. S. 581 , 596597 (1926) (rejecting claim of distinguished
physician because "[h]igh medical authority being in conflict ... ,
it would, indeed, be strange if Congress lacked the power [to
act]"); Marshall v. United States, 414 U. S. 417 , 427 (1974)
(recognizing "there is no agreement among members of the medical
profession" (internal quotation marks omitted)); United
States v. Rutherford, 442 U. S. 544 (1979)
(discussing regulatory approval process for certain drugs).

															Instructive is Jacobson v. Massachusetts, 197 U. S. 11 (1905), where
the defendant was convicted because he refused to undergo a
smallpox vaccination. The defendant claimed the mandatory
vaccination violated his liberty to "care for his own body and
health in such way as to him 971 seems best." Id., at 26. He offered to prove that members
of the medical profession took the position that the vaccination
was of no value and, in fact, was harmful. Id., at 30. The
Court rejected the claim, establishing beyond doubt the right of
the legislature to resolve matters upon which physicians
disagreed: "Those offers [of proof by the defendant] in the main seem to
have had no purpose except to state the general theory of those of
the medical profession who attach little or no value to vaccination
as a means of preventing the spread of smallpox, or who think that
vaccination causes other diseases of the body. What everybody knows
the court must know, and therefore the state court judicially knew,
as this court knows, that an opposite theory accords with the
common belief, and is maintained by high medical authority. We must
assume that, when the statute in question was passed, the
legislature of Massachusetts was not unaware of these opposing
theories, and was compelled, of necessity, to choose between them.
It was not compelled to commit a matter involving the public health
and safety to the final decision of a court or jury. It is no part
of the function of a court or a jury to determine which one of two
modes was likely to be the most effective for the protection of the
public against disease. That was for the legislative department to
determine in the light of all the information it had or could
obtain. It could not properly abdicate its function to guard the
public health and safety." Ibid. The Jacobson Court quoted with approval a recent
statecourt decision which observed, in words having full
application today: "The fact that the belief is not universal [in the medical
community] is not controlling, for there is scarcely any belief
that is accepted by everyone. The possibility that 972 the belief may be wrong, and that science may yet show it to be
wrong, is not conclusive; for the legislature has the right to pass
laws which, according to common belief of the people, are adapted
to [address medical matters]. In a free country, where government
is by the people, through their chosen representatives, practical
legislation admits of no other standard of action.'" Id., at
35 (quoting Viemester v. White, 179 N. Y. 235, 241,
72 N. E. 97, 99 (1904)). JUSTICE O'CONNOR assures the people of Nebraska they are free to
redraft the law to include an exception permitting the D&X to
be performed when "the procedure, in appropriate medical judgment,
is necessary to preserve the health of the mother." Ante, at
951. The assurance is meaningless. She has joined an opinion which
accepts that Dr. Carhart exercises "appropriate medical judgment"
in using the D&X for every patient in every procedure,
regardless ofindications, after 15 weeks' gestation. Ante, at 937 (requiring any health exception to "tolerate responsible
differences of medical opinion" which "are present here"). A ban
which depends on the "appropriate medical judgment" of Dr. Carhart
is no ban at all. He will be unaffected by any new legislation.
This, of course, is the vice of a health exception resting in the
physician's discretion.

															In light of divided medical opinion on the propriety of the
partial birth abortion technique (both in terms of physical safety
and ethical practice) and the vital interests asserted by Nebraska
in its law, one is left to ask what the first Justice Harlan asked:
"Upon what sound principles as to the relations existing between
the different departments of government can the court review this
action of the legislature?" Jacobson, supra, at 31. The
answer is none.

															III

															The Court's next holding is that Nebraska's ban forbids both the
D&X procedure and the more common D&E proce- 973 dure. In so ruling the Court misapplies settled doctrines of
statutory construction and contradicts Casey's premise that
the States have a vital constitutional position in the abortion
debate. I agree with the careful statutory analysis conducted by
JUSTICE THOMAS, post, at 989-1005. Like the ruling requiring
a physician veto, requiring a State to meet unattainable standards
of statutory draftsmanship in order to have its voice heard on this
grave and difficult subject is no different from foreclosing state
participation altogether.

															Nebraska's statute provides: "No partial birth abortion shall be performed in this state
unless such procedure is necessary to save the life of the mother
whose life is endangered by a physical disorder, physical illness,
or physical injury, including a life-endangering physical condition
caused by or arising from the pregnancy itself." Neb. Rev. Stat.
Ann. § 28-328(1) (Supp. 1999). The statute defines "partial birth abortion" as "an abortion procedure in which the person performing the
abortion partially delivers vaginally a living unborn child before
killing the unborn child and completing the delivery." §
28-326(9). It further defines "partially delivers vaginally a living unborn
child before killing the unborn child" to mean "deliberately and intentionally delivering into the vagina a
living unborn child, or a substantial portion thereof, for the
purpose of performing a procedure that the person performing such
procedure knows will kill the unborn child and does kill the unborn
child." Ibid. The text demonstrates the law applies only to the D&X
procedure. Nebraska's intention is demonstrated at three points in
the statutory language: references to "partial-birth abortion" and
to the "delivery" of a fetus; and the require- 974 ment that the delivery occur "before" the performance of the
death-causing procedure.

															The term "partial birth abortion" means an abortion performed
using the D&X method as described above. The Court of Appeals
acknowledged the term "is commonly understood to refer to a
particular procedure known as intact dilation and extraction
(D&X)." Little Rock Family Planning Servs. v. Jegley, 192 F.3d
794 , 795 (CA8 1999). Dr. Carhart's own lead expert, Dr.
Phillip Stubblefield, prefaced his description of the D&X
procedure by describing it as the procedure "which, in the lay
press, has been called a partial-birth abortion." App. 271-272. And
the AMA has declared: "The 'partial birth abortion' legislation is
by its very name aimed exclusively [at the D&X.] There is no
other abortion procedure which could be confused with that
description." AMA Factsheet 3. A commonsense understanding of the
statute's reference to "partial-birth abortion" demonstrates its
intended reach and provides all citizens the fair warning required
by the law. McBoyle v. United States, 283 U. S. 25 , 27
(1931).

															The statute's intended scope is demonstrated by its requirement
that the banned procedure include a partial "delivery" of the fetus
into the vagina and the completion of a "delivery" at the end of
the procedure. Only removal of an intact fetus can be described as
a "delivery" of a fetus and only the D&X involves an intact
fetus. In a D&E, portions of the fetus are pulled into the
vagina with the intention of dismembering the fetus by using the
traction at the opening between the uterus and vagina. This cannot
be considered a delivery of a portion of a fetus. In Dr. Carhart's
own words, the D&E leaves the abortionist with a "tray full of
pieces," App. 125, at the end of the procedure. Even if it could be
argued, as the majority does, ante, at 944, that dragging a
portion of an intact fetus into the vagina as the first step of a
D&E is a delivery of that portion of an intact fetus, the
D&E still does not involve "completing the deliv- 975 ery" of an intact fetus. Whatever the statutory term "completing
the delivery" of an unborn child means, it cannot mean, as the
Court would have it, placing fetal remains on a tray. See Planned Parenthood of Wis. v. Doyle, 9 F. Supp. 2d
1033, 1041 (WD Wis. 1998) (the statute is "readily applied to the
partial delivery of an intact child but hardly applicable to the
delivery of dismembered body parts").

															Medical descriptions of the abortion procedures confirm the
point, for it is only the description of the D&X that invokes
the word "delivery." App. 600. The United States, as amicus, cannot bring itself to describe the D&E as involving a
"delivery," instead substituting the word "emerges" to describe how
the fetus is brought into the vagina in a D&E. Brief for United
States as Amicus Curiae 10. The Court, in a similar
admission, uses the words "a physician pulling" a portion of a
fetus, ante, at 939, rather than a "physician delivering" a
portion of a fetus; yet only a procedure involving a delivery is
banned by the law. Of all the definitions of "delivery" provided by
the Court, ante, at 944, not one supports (or, more
important for statutory construction purposes, requires) the
conclusion that the statutory term "completing the delivery" refers
to the placement of dismembered body parts on a tray rather than
the removal of an intact fetus from the woman's body.

															The operation of Nebraska's law is further defined by the
requirement that the fetus be partially delivered into the vagina
"before" the abortionist kills it. The partial delivery must be
undertaken "for the purpose of performing a procedure that the
person ... knows will kill the unborn child." Neb. Rev. Stat. Ann.
§ 28-326(9) (Supp. 1999). The law is most naturally read to require
the death of the fetus to take place in two steps: First the fetus
must be partially delivered into the vagina and then the defendant
must perform a death-causing procedure. In a D&E, forcing the
fetus into the vagina (the pulling of extremities off the body in
the process of extracting the body parts from the uterus into
the 976 vagina) is also the procedure that kills the fetus. Richmond
Medical Center for Women v. Gilmore, 144 F. 3d, at 330
(order of Luttig, J.). In a D&X, the fetus is partially
delivered into the vagina before a separate procedure (the socalled
"reduction procedure") is performed in order to kill the fetus.

															The majority rejects this argument based on its conclusion that
the word "procedure" must "refer to an entire abortion procedure"
each time it is used. Ante, at 944. This interpretation
makes no sense. It would require us to conclude that the Nebraska
Legislature considered the "entire abortion procedure" to take
place after the abortionist has already delivered into the vagina a
living unborn child, or a substantial portion thereof. Neb. Rev.
Stat. Ann. § 28326(9) (Supp. 1999). All medical authorities agree,
however, that the entire abortion procedure begins several days
before this stage, with the dilation of the cervix. The majority
asks us, in effect, to replace the words "for the purpose of
performing" with the words "in the course of performing" in the
portion of § 28-326(9) quoted in the preceding paragraph. The
reference to "procedure" refers to the separate deathcausing
procedure that is unique to the D&X.

															In light of the statutory text, the commonsense understanding
must be that the statute covers only the D&X. See Broadrick v. Oklahoma, 413 U. S. 601 , 698
(1973). The AMA does not disagree. It writes: "The partial birth
abortion legislation is by its very name aimed exclusively at a
procedure by which a living fetus is intentionally and deliberately
given partial birth and delivered for the purpose of killing it.
There is no other abortion procedure which could be confused with
that description." AMA Factsheet 3 (internal quotation marks
omitted). Casey disavows strict scrutiny review; and
Nebraska must be afforded leeway when attempting to regulate the
medical profession. See Kansas v. Hendricks, 521 U.
S., at 359 ("[WJe have traditionally left to legislators the task
of defining terms of a medical 977 nature that have legal significance"). To hold the statute
covers the D&E, the Court must disagree with the AMA and
disregard the known intent of the legislature, adequately expressed
in the statute.

															Strained statutory constructions in abortion cases are not new,
for JUSTICE O'CONNOR identified years ago "an unprecedented canon
of construction under which in cases involving abortion, a
permissible reading of a statute is to be avoided at all costs." Thornburgh v. American College of Obstetricians and
Gynecologists, 476 U. S. 747 , 829 (1986)
(dissenting opinion) (internal quotation marks omitted). Casey banished this doctrine from our jurisprudence; yet the
Court today reinvigorates it and, in the process, ignores its
obligation to interpret the law in a manner to validate it, not
render it void. E. g., Johnson v. Robison, 415 U. S. 361 , 366367
(1974); Edward J. DeBartolo Corp. v. Florida Gulf Coast Building & Constr. Trades
Council, 485 U.
S. 568 , 575 (1988). Avoidance of unconstitutional constructions
is discussed only in two sentences of the Court's analysis and
dismissed as inapplicable because the statute is not susceptible to
the construction offered by the Nebraska Attorney General. Ante, at 944-945. For the reasons here discussed, the
statute is susceptible to the construction; and the Court is
required to adopt it.

															The Court and JUSTICE O'CONNOR seek to shield themselves from
criticism by citing the interpretations of the partial birth
abortion statutes offered by some other federal courts. Ante, at 941-942. On this issue of nationwide importance,
these courts have no special competence; and of appellate courts to
consider similar statutes, a majority have, in contrast to the
Court, declared that the law could be interpreted to cover only the
D&X. See Hope Clinic, 195 F.3d, at 865-871; Richmond
Medical Center, supra, at 330-332 (order of Luttig, J.). Thirty
States have enacted similar laws. It is an abdication of
responsibility for the Court to suggest its hands are tied by
decisions which paid scant at- 978 tention to Casey's recognition of the State's authority
and misapplied the doctrine of construing statutes to avoid
constitutional difficulty. Further, the leading case describing the
deference argument, Frisby v. Schultz, 487 U. S. 474 , 483
(1988), declined to defer to a lower court construction of the
state statute at issue in the case. As Frisby observed, the
"lower courts ran afoul of the well-established principle that
statutes will be interpreted to avoid constitutional difficulties."
See also Webster v. Reproductive Health Services, 492 U. S. 490 ,
514 (1989) (opinion of REHNQUIST, C. J.); id., at 525
(O'CONNOR, J., concurring in part and concurring in judgment).

															The majority and, even more so, the concurring opinion by
JUSTICE O'CONNOR, ignore the settled rule against deciding
unnecessary constitutional questions. The State of N ebraska
conceded, under its understanding of Casey, that if this law
must be interpreted to bar D&E as well as D&X it is
unconstitutional. Since the majority concludes this is indeed the
case, that should have been the end of the matter. Yet the Court
and JUSTICE O'CONNOR go much further. They conclude that the
statute requires a health exception which, for all practical
purposes and certainly in the circumstances of this case, allows
the physician to make the determination in his own professional
judgment. This is an immense constitutional holding. It is
unnecessary; and, for the reasons I have sought to explain, it is
incorrect. While it is not clear which of the two halves of the
majority opinion is dictum, both are wrong.

															The United States District Court in this case leaped to prevent
the law from being enforced, granting an injunction before it was
applied or interpreted by Nebraska. Cf. Hill v. Colorado,
ante, p. 703. In so doing, the court excluded from the abortion
debate not just the Nebraska legislative branch but the State's
executive and judiciary as well. The law was enjoined before the
chief law enforcement officer 979 of the State, its Attorney General, had any opportunity to
interpret it. The federal court then ignored the representations
made by that officer during this litigation. In like manner,
Nebraska's courts will be given no opportunity to define the
contours of the law, although by all indications those courts would
give the statute a more narrow construction than the one so eagerly
adopted by the Court today. E. g., Stenberg v. Moore, 258 Neb. 199,206,602 N. W. 2d 465, 472 (1995). Thus the court
denied each branch of Nebraska's government any role in the
interpretation or enforcement of the statute. This cannot be what Casey meant when it said we would be more solicitous of
state attempts to vindicate interests related to abortion. Casey did not assume this state of affairs.

															IV

															Ignoring substantial medical and ethical opinion, the Court
substitutes its own judgment for the judgment of Nebraska and some
30 other States and sweeps the law away. The Court's holding stems
from misunderstanding the record, misinterpretation of Casey, outright refusal to respect the law of a State, and
statutory construction in conflict with settled rules. The decision
nullifies a law expressing the will of the people of Nebraska that
medical procedures must be governed by moral principles having
their foundation in the intrinsic value of human life, including
the life of the unborn. Through their law the people of Nebraska
were forthright in confronting an issue of immense moral
consequence. The State chose to forbid a procedure many decent and
civilized people find so abhorrent as to be among the most serious
of crimes against human life, while the State still protected the
woman's autonomous right of choice as reaffirmed in Casey. The Court closes its eyes to these profound concerns.

															From the decision, the reasoning, and the judgment, I
dissent. 980 JUSTICE THOMAS, with whom THE CHIEF JUSTICE and JUSTICE SCALIA
join, dissenting.

															In 1973, this Court struck down an Act of the Texas Legislature
that had been in effect since 1857, thereby rendering
unconstitutional abortion statutes in dozens of States. Roe v. Wade, 410
U. S. 113 , 119. As some of my colleagues on the Court, past and
present, ably demonstrated, that decision was grievously wrong.
See, e. g., Doe v. Bolton, 410 U. S. 179 , 221-223
(1973) (White, J., dissenting); Roe v. Wade, supra, at 171-178 (REHNQUIST, J., dissenting). Abortion is a unique act,
in which a woman's exercise of control over her own body ends,
depending on one's view, human life or potential human life.
Nothing in our Federal Constitution deprives the people of this
country of the right to determine whether the consequences of
abortion to the fetus and to society outweigh the burden of an
unwanted pregnancy on the mother. Although a State may permit abortion, nothing in the Constitution dictates that a State must do so.

															In the years following Roe, this Court applied, and,
worse, extended, that decision to strike down numerous state
statutes that purportedly threatened a woman's ability to obtain an
abortion. The Court voided parental consent laws, see Planned
Parenthood of Central Mo. v. Danforth, 428 U. S. 52 , 75 (1976),
legislation requiring that second-trimester abortions take place in
hospitals, see Akron v. Akron Center for Reproductive
Health, Inc., 462
U. S. 416 , 431 (1983), and even a requirement that both parents
of a minor be notified before their child has an abortion, see Hodgson v. Minnesota, 497 U. S. 417 , 455
(1990). It was only a slight exaggeration when this Court
described, in 1976, a right to abortion "without interference from
the State." Danforth, supra, at 61. The Court's expansive
application of Roe in this period, even more than Roe itself, was fairly described as the "unrestrained imposition of
[the Court's] own, extraconstitutional value preferences" on the
American people. Thornburgh v. 981 American College of Obstetricians and Gynecologists, 476 U. S. 747 , 794 (1986)
(White, J., dissenting).

															It appeared that this era of Court-mandated abortion on demand
had come to an end, first with our decision in Web ster v. Reproductive Health Services, 492 U. S. 490 (1989), see id., at 557 (Blackmun, J., concurring in part and dissenting
in part) (lamenting that the plurality had "discard[ed]" Roe), and then finally (or so we were told) in our decision
in Planned Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 (1992). Although in Casey the separate opinions of THE CHIEF
JUSTICE and JUSTICE SCALIA urging the Court to overrule Roe did not command a majority, seven Members of that Court, including
six Members sitting today, acknowledged that States have a
legitimate role in regulating abortion and recognized the States'
interest in respecting fetal life at all stages of development. See
505 U. S., at 877 (joint opinion of O'CONNOR, KENNEDY, and SOUTER,
JJ.); id., at 944 (REHNQUIST, C. J., joined by White,
SCALIA, and THOMAS, JJ., concurring in judgment in part and
dissenting in part); id., at 979 (SCALIA, J., joined by
REHNQUIST, C. J., and White and THOMAS, JJ., concurring in judgment
in part and dissenting in part). The plurality authored by JUSTICES
O'CONNOR, KENNEDY, and SOUTER concluded that prior case law "went
too far" in "undervalu[ing] the State's interest in potentiallife"
and in "striking down ... some abortion regulations which in no
real sense deprived women of the ultimate decision." Id., at
875.1 Roe and subsequent cases, according to the plurality,
had wrongly "treat[ed] all governmental attempts to influence a
woman's decision on behalf of the potential life within her as
unwarranted," a treatment that was "incompatible with the
recognition that there is a substantial state interest in potential
life throughout pregnancy." Id., at 876. Accordingly, the
plurality held that so

															1 Unless otherwise noted, all subsequent cites of Planned
Parenthood of Southeastern Pa. v. Casey, 505 U. S. 833 (1992), are
to the joint opinion of O'CONNOR, KENNEDY, and SOUTER, JJ. 982 long as state regulation of abortion furthers legitimate
interests-that is, interests not designed to strike at the right
itself-the regulation is invalid only if it imposes an undue burden
on a woman's ability to obtain an abortion, meaning that it places
a substantial obstacle in the woman's path. Id., at
874, 877.

															My views on the merits of the Casey plurality have been
fully articulated by others. Id., at 944 (REHNQUIST, C. J.,
concurring in judgment in part and dissenting in part); id., at 979 (SCALIA, J., concurring in judgment in part and dissenting
in part). I will not restate those views here, except to note that
the Casey plurality opinion was constructed by its authors
out of whole cloth. The standard set forth in the Casey plurality has no historical or doctrinal pedigree. The standard is
a product of its authors' own philosophical views about abortion,
and it should go without saying that it has no origins in or
relationship to the Constitution and is, consequently, as
illegitimate as the standard it purported to replace. Even
assuming, however, as I will for the remainder of this dissent,
that Casey's fabricated undue-burden standard merits
adherence (which it does not), to day's decision is extraordinary.
Today, the Court inexplicably holds that the States cannot
constitutionally prohibit a method of abortion that millions find
hard to distinguish from infanticide and that the Court hesitates
even to describe. Ante, at 923. This holding cannot be
reconciled with Casey's undue-burden standard, as that
standard was explained to us by the authors of the plurality
opinion, and the majority hardly pretends otherwise. In striking
down this statute-which expresses a profound and legitimate respect
for fetal life and which leaves unimpeded several other safe forms
of abortion-the majority opinion gives the lie to the promise of Casey that regulations that do no more than "express
profound respect for the life of the unborn are permitted, if they
are not a substantial obstacle to the woman's exercise of the right
to choose" whether or not to have an abortion. 505 983 u. S., at 877. Today's decision is so obviously irreconcilable
with Casey's explication of what its undue-burden standard
requires, let alone the Constitution, that it should be seen for
what it is, a reinstitution of the pre-Webster abortion-ondemand era in which the mere invocation of "abortion
rights" trumps any contrary societal interest. If this statute is
unconstitutional under Casey, then Casey meant
nothing at all, and the Court should candidly admit it.

															To reach its decision, the majority must take a series of
indefensible steps. The majority must first disregard the
principles that this Court follows in every context but abortion:
We interpret statutes according to their plain meaning, and we do
not strike down statutes susceptible of a narrowing construction.
The majority also must disregard the very constitutional standard
it purports to employ, and then displace the considered judgment of
the people of Nebraska and 29 other States. The majority's decision
is lamentable, because of the result the majority reaches, the
illogical steps the majority takes to reach it, and because it
portends a return to an era I had thought we had at last
abandoned.

															I

															In the almost 30 years since Roe, this Court has never
described the various methods of aborting a second- or
third-trimester fetus. From reading the majority's sanitized
description, one would think that this case involves state
regulation of a widely accepted routine medical procedure. Nothing
could be further from the truth. The most widely used method of
abortion during this stage of pregnancy is so gruesome that its use
can be traumatic even for the physicians and medical staff who
perform it. See App. 656 (testimony of Dr. Boehm); W. Hern,
Abortion Practice 134 (1990). And the particular procedure at issue
in this case, "partial birth abortion," so closely borders on
infanticide that 30 States have attempted to ban it. I will begin
with a discussion of the methods of abortion available to 984 women late in their pregnancies before addressing the statutory
and constitutional questions involved.2

															1. The primary form of abortion used at or after 16 weeks'
gestation is known as "dilation and evacuation" or "D&E." 11 F.
Supp. 2d 1099, 1103, 1129 (Neb. 1998). When performed during that
stage of pregnancy, the D&E procedure requires the physician to
dilate the woman's cervix and then extract the fetus from her
uterus with forceps. Id., at 1103; App. 490 (American
Medical Association (AMA), Report of the Board of Trustees on
Late-Term Abortion). Because of the fetus' size at this stage, the
physician generally removes the fetus by dismembering the fetus one
piece at a time.3 11 F. Supp. 2d, at 1103-1104. The doctor grabs a
fetal extremity, such as an arm or a leg, with forceps and "pulls
it through the cervical os ... tearing ... fetal parts from the
fetal body ... by means of traction." Id., at 1104. See App.
55 (testimony of Dr. Carhart). In other words, the physician will
grasp the fetal parts and "basically tear off pieces of the fetus
and pull them out." Id., at 267 (testimony of Dr.
Stubblefield). See also id., at 149 (testimony of

															2 In 1996, the most recent year for which abortion statistics
are available from the Centers for Disease Control and Prevention,
there were approximately 1,221,585 abortions performed in the
United States. Centers for Disease Control and Prevention, Abortion
Surveillance-United States, 1996, p. 1 (July 30, 1999). Of these
abortions, about 67,000-5.5%-were performed in or after the 16th
week of gestation, that is, from the middle of the second trimester
through the third trimester. Id., at 5. The majority
apparently accepts that none of the abortion procedures used for
pregnancies in earlier stages of gestation, including "dilation and
evacuation" (D&E) as it is practiced between 13 and 15 weeks'
gestation, would be compromised by the statute. See ante, at
938-940 (concluding that the statute could be interpreted to apply
to instrumental dismemberment procedures used in a later term
D&E). Therefore, only the methods of abortion available to
women in this later stage of pregnancy are at issue in this
case.

															3 At 16 weeks' gestation, the average fetus is approximately six
inches long. By 20 weeks' gestation, the fetus is approximately
eight inches long. K. Moore & T. Persaud, The Developing Human
112 (6th ed. 1998). 985 Dr. Hodgson) ("[Y]ou grasp the fetal parts, and you often don't
know what they are, and you try to pull it down, and its ... simply
all there is to it"). The fetus will die from blood loss, either
because the physician has separated the umbilical cord prior to
beginning the procedure or because the fetus loses blood as its
limbs are removed. Id., at 6264 (testimony of Dr. Carhart); id., at 151 (testimony of Dr. Hodgson).4 When all of the
fetus' limbs have been removed and only the head is left in utero,
the physician will then collapse the skull and pull it through the
cervical canal. Id., at 106 (testimony of Dr. Carhart); id., at 297 (testimony of Dr. Stubblefield); Causeway
Medical Suite v. Foster, 43 F. Supp. 2d 604, 608 (ED La.
1999). At the end of the procedure, the physician is left, in
respondent's words, with a "tray full of pieces." App. 125
(testimony of Dr. Carhart).

															2. Some abortions after the 15th week are performed using a
method of abortion known as induction. 11 F. Supp. 2d, at 1108;
App. 492 (AMA, Report of the Board of Trustees on Late-Term
Abortion). In an induction procedure, the amniotic sac is injected
with an abortifacient such as a saline solution or a solution that
contains prostaglandin. 11 F. Supp. 2d, at 1108. Uterine
contractions typically follow, causing the fetus to be expelled. Ibid. 3. A third form of abortion for use during or after 16 weeks'
gestation is referred to by some medical professionals as "intact
D&E." There are two variations of this method, both of which
require the physician to dilate the woman's cervix. Gynecologic,
Obstetric, and Related Surgery 1043 (D. Nichols & D.
Clarke-Pearson eds., 2d ed. 2000); App. 271 (testimony of Dr.
Stubblefield). The first variation is used only in vertex
presentations, that is, when the fetal head is presented first. To
perform a vertex-presentation intact D&E, the doctor will
insert an instrument into the fetus'

															4 Past the 20th week of gestation, respondent attempts to induce
fetal death by injection prior to beginning the procedure in
patients. 11 F. supp. 2d, at 1106; App. 64. 986 skull while the fetus is still in utero and remove the brain and
other intracranial contents. 11 F. Supp. 2d, at 1111; Gynecologic,
Obstetric, and Related Surgery, supra, at 1043; App. 271
(testimony of Dr. Stubblefield). When the fetal skull collapses,
the physician will remove the fetus.

															The second variation of intact D&E is the procedure commonly
known as "partial birth abortion." 5 11 F. Supp. 2d, at 1106;
Gynecologic, Obstetric, and Related Surgery, supra, at 1043;
App. 271 (testimony of Dr. Stubblefield). This procedure, which is
used only rarely, is performed on mid- to late-second-trimester
(and sometimes third-trimester) fetuses.6 Although there are
variations, it is generally per-

															5 There is a disagreement among the parties regarding the
appropriate term for this procedure. Congress and numerous state
legislatures, including Nebraska's, have described this procedure
as "partial birth abortion," reflecting the fact that the fetus is
all but born when the physician causes its death. See infra this page and 987. Respondent prefers to refer generically to
"intact dilation and evacuation" or "intact D&E" without
reference to whether the fetus is presented head first or feet
first. One of the doctors who developed the procedure, Martin
Haskell, described it as "Dilation and Extraction" or "D&X."
See The Partial-Birth Abortion Ban Act of 1995, Hearing on H. R.
1833 before the Senate Committee on the Judiciary, 104th Cong., 1st
Sess., 5 (1995) (hereinafter H. R. 1833 Hearing). The Executive
Board of the American College of Obstetricians and Gynecologists
(ACOG) refers to the procedure by the hybrid term "intact dilation
and extraction" or "intact D&X," see App. 599 (ACOG Executive
Board, Statement on Intact Dilation and Extraction (Jan. 12,
1997)), which term was adopted by the AMA, see id., at 492
(AMA, Report of the Board of Trustees on Late-Term Abortion). I
will use the term "partial birth abortion" to describe the
procedure because it is the legal term preferred by 28 state
legislatures, including the State of Nebraska, and by the United
States Congress. As I will discuss, see infra, at 999-1001,
there is no justification for the majority's preference for the
terms "breech-conversion intact D&E" and "D&X" other than
the desire to make this procedure appear to be medically
sanctioned.

															6 There is apparently no general understanding of which women
are appropriate candidates for the procedure. Respondent uses the
procedure on women at 16 to 20 weeks' gestation. 11 F. Supp. 2d, at
1105. The doctor who developed the procedure, Dr. Martin Haskell,
indicated that he 987 formed as follows: After dilating the cervix, the physician will
grab the fetus by its feet and pull the fetal body out of the
uterus into the vaginal cavity. 11 F. Supp. 2d, at 1106. At this
stage of development, the head is the largest part of the body.
Assuming the physician has performed the dilation procedure
correctly, the head will be held inside the uterus by the woman's
cervix. Ibid.; H. R. 1833 Hearing 8. While the fetus is
stuck in this position, dangling partly out of the woman's body,
and just a few inches from a completed birth, the physician uses an
instrument such as a pair of scissors to tear or perforate the
skull. 11 F. Supp. 2d, at 1106; App. 664 (testimony of Dr. Boehm);
Joint Hearing on S. 6 and H. R. 929 before the Senate Committee on
the Judiciary and the Subcommittee on the Constitution of the House
Committee on the Judiciary, 105th Cong., 1st Sess., 45 (1995)
(hereinafter S. 6 and H. R. 929 Joint Hearing). The physician will
then either crush the skull or will use a vacuum to remove the
brain and other intracranial contents from the fetal skull,
collapse the fetus' head, and pull the fetus from the uterus. 11 F.
Supp. 2d, at 1106.7

															Use of the partial birth abortion procedure achieved prominence
as a national issue after it was publicly described by Dr. Martin
Haskell, in a paper entitled "Dilation and Extraction for Late
Second Trimester Abortion," at the National Abortion Federation's
September 1992 Risk Management Seminar. In that paper, Dr. Haskell
described his version of the procedure as follows: "With a lower [fetal] extremity in the vagina, the surgeon uses
his fingers to deliver the opposite lower performed the procedure on patients 20 through 24 weeks and on
certain patients 25 through 26 weeks. See H. R. 1833 Hearing
36.

															7 There are, in addition, two forms of abortion that are used
only rarely: hysterotomy, a procedure resembling a Caesarean
section, requires the surgical delivery of the fetus through an
incision on the uterine wall, and hysterectomy. 11 F. Supp. 2d, at
1109. 988 extremity, then the torso, the shoulders and the upper
extremities. "The skull lodges at the internal cervical os. Usually there is
not enough dilation for it to pass through. The fetus is oriented
dorsum or spine up. "At this point, the right-handed surgeon slides the fingers of
the left hand along the back of the fetus and 'hooks' the shoulders
of the fetus with the index and ring fingers (palm down). "[T]he surgeon takes a pair of blunt curved Metzenbaum scissors
in the right hand. He carefully advances the tip, curved down,
along the spine and under his middle finger until he feels it
contact the base of the skull under the tip of his middle
finger. "[T]he surgeon then forces the scissors into the base of the
skull or into the foramen magnum. Having safely entered the skull,
he spreads the scissors to enlarge the opening. "The surgeon removes the scissors and introduces a suction
catheter into this hole and evacuates the skull contents. With the
catheter still in place, he applies traction to the fetus, removing
it completely from the patient." H. R. 1833 Hearing 3, 8-9. In cases in which the physician inadvertently dilates the woman
to too great a degree, the physician will have to hold the fetus
inside the woman so that he can perform the procedure. Id., at 80 (statement of Pamela Smith, M. D.) ("In these procedures, one
basically relies on cervical entrapment of the head, along with a
firm grip, to help keep the baby in place while the practitioner
plunges a pair of scissors into the base of the baby's skull"). See
also S. 6 and H. R. 929 Joint Hearing 45 ("I could put dilapan in
for four or five days and say I'm doing a D&E procedure and the
fetus could just fall out. But that's not really the point. The
point here is you're attempting to do an abortion .... Not to see
how do 989 I manipulate the situation so that I get a live birth instead")
(quoting Dr. Haskell).

															II

															Nebraska, along with 29 other States, has attempted to ban the
partial birth abortion procedure. Although the Nebraska statute
purports to prohibit only "partial birth abortion," a phrase which
is commonly used, as I mentioned, to refer to the breech extraction
version of intact D&E, the majority concludes that this statute
could also be read in some future case to prohibit ordinary
D&E, the first procedure described above. According to the
majority, such an application would pose a substantial obstacle to
some women seeking abortions and, therefore, the statute is
unconstitutional. The majority errs with its very first step. I
think it is clear that the Nebraska statute does not prohibit the
D&E procedure. The Nebraska partial birth abortion statute at
issue in this case reads as follows: "No partial-birth abortion shall be performed in this state,
unless such procedure is necessary to save the life of the mother
whose life is endangered by a physical disorder, physical illness,
or physical injury, including a life-endangering physical condition
caused by or arising from the pregnancy itself." Neb. Rev. Stat.
Ann. § 28-328(1) (Supp. 1999). "Partial birth abortion" is defined in the statute as "an abortion procedure in which the person performing the
abortion partially delivers vaginally a living unborn child before
killing the unborn child and completing the delivery. For purposes
of this subdivision, the term partially delivers vaginally a living
unborn child before killing the unborn child means deliberately and
intentionally delivering into the vagina a living unborn child, or
a substantial portion thereof, for the purpose of performing a
procedure that the person performing such 990 procedure knows will kill the unborn child and does kill the
unborn child." § 28-326(9).

															A

															Starting with the statutory definition of "partial birth
abortion," I think it highly doubtful that the statute could be
applied to ordinary D&E. First, the Nebraska statute applies
only if the physician "partially delivers vaginally a living
unborn child," which phrase is defined to mean "deliberately and
intentionally delivering into the vagina a living unborn
child, or a substantial portion thereof." § 28-326(9) (emphases
added). When read in context, the term "partially delivers" cannot
be fairly interpreted to include removing pieces of an unborn child
from the uterus one at a time.

															The word "deliver," particularly delivery of an "unborn child,"
refers to the process of "assist[ing] in giving birth," which
suggests removing an intact unborn child from the womb, rather than
pieces of a child. See Webster's Ninth New Collegiate Dictionary
336 (1991) (defining "deliver" as "to assist in giving birth; to
aid in the birth of"); Stedman's Medical Dictionary 409 (26th ed.
1995) ("To assist a woman in childbirth"). Without question, one
does not "deliver" a child when one removes the child from the
uterus piece by piece, as in a D&E. Rather, in the words of
respondent and his experts, one "remove[s]" or "dismember[s]" the
child in a D&E. App. 45, 55 (testimony of Dr. Carhart)
(referring to the act of removing the fetus in a D&E); id., at 150 (testimony of Dr. Hodgson) (same); id., at 267 (testimony of Dr. Stubblefield) (physician "dismember[s]"
the fetus). See also H. R. 1833 Hearing 3, 8 (Dr. Haskell
describing "delivery" of part of the fetus during a D&X). The
majority cites sources using the terms "deliver" and "delivery" to
refer to removal of the fetus and the placenta during birth. But
these sources also presume an intact fetus, rather than dismembered
fetal parts. See Obstetrics: Normal & Problem Pregnancies 388
(S. Gabbe, J. Niebyl, & J. Simpson eds., 3d 991 ed. 1996) ("After delivery [of infant and placenta], the
placenta, cord, and membranes should be examined"); 4 Oxford
English Dictionary 421, 422 (2d ed. 1989) ("To disburden (a woman)
of the foetus, to bring to childbirth"); B. Maloy, Medical
Dictionary for Lawyers 221 (2d ed. 1989) ("To aid in the process of
childbirth; to bring forth; to deliver the fetus, placenta"). The
majority has pointed to no source in which "delivery" is used to
refer to removal of first a fetal arm, then a leg, then the torso,
etc. In fact, even the majority describes the D&E procedure
without using the word "deliver" to refer to the removal of fetal
tissue from the uterus. See ante, at 939 ("pulling a
'substantial portion' of a still living fetus" (emphasis added)); ibid. ("portion of a living fetus has been pulled into the vagina" (emphasis added)). No one, including the majority,
understands the act of pulling off a part of a fetus to be a
"delivery."

															To make the statute's meaning even more clear, the statute
applies only if the physician "partially delivers vaginally a
living unborn child before killing the unborn child and
completing the delivery." The statute defines this phrase to mean
that the physician must complete the delivery "for the purpose
of performing a procedure" that will kill the unborn child. It
is clear from these phrases that the procedure that kills the fetus
must be subsequent to, and therefore separate from, the "partia[l]
deliver[y]" or the "deliver[y] into the vagina" of "a living unborn
child or substantial portion thereof." In other words, even if one
assumes, arguendo, that dismemberment-the act of grasping a
fetal arm or leg and pulling until it comes off, leaving the
remaining part of the fetal body still in the uterus-is a kind of
"delivery," it does not take place "before" the death-causing
procedure or "for the purpose of performing" the death-causing
procedure; it is the death-causing procedure. Under the
majority's view, D&E is covered by the statute because when the
doctor pulls on a fetal foot until it tears off he has "delivered"
a substantial portion of the unborn child and has performed 992 a procedure known to cause death. But, significantly, the
physician has not "delivered" the child before performing
the death-causing procedure or "for the purpose of" performing the
death-causing procedure; the dismemberment "delivery" is itself the
act that causes the fetus' death.8

															Moreover, even if removal of a fetal foot or arm from the uterus
incidental to severing it from the rest of the fetal body could
amount to delivery before, or for the purpose of, performing a death-causing procedure, the delivery would not be of
an "unborn child, or a substantial portion thereof." And even
supposing that a fetal foot or arm could conceivably be a
"substantial portion" of an unborn child, both the common
understanding of "partial birth abortion" and the principle that
statutes will be interpreted to avoid constitutional difficulties
would require one to read "substantial" otherwise. See infra, at 996-997.

															B

															Although I think that the text of § 28-326(9) forecloses any
application of the Nebraska statute to the D&E procedure, even
if there were any ambiguity, the ambiguity would be conclusively
resolved by reading the definition in light of the fact that the
Nebraska statute, by its own terms, applies only to "partial birth
abortion," § 28-328(1). By ordinary rules of statutory
interpretation, we should resolve any ambiguity in the specific
statutory definition to comport with the common understanding of
"partial birth abortion," for that term itself, no less than the
specific definition, is part of the stat-

															8 The majority argues that the statute does not explicitly
require that the death-causing procedure be separate from the
overall abortion procedure. That is beside the point; under the
statute the death-causing procedure must be separate from the delivery. Moreover, it is incorrect to state that the
statute contemplates only one "procedure." The statute clearly uses
the term "procedure" to refer to both the overall abortion
procedure ("partial birth abortion" is "an abortion procedure") as
well as to a component of the overall abortion procedure ("for the
purpose of performing a procedure ... that will kill the unborn
child"). 993 ute. United States v. Morton, 467 U. S. 822 , 828 (1984)
("We do not ... construe statutory phrases in isolation; we read
statutes as a whole").9

															"Partial birth abortion" is a term that has been used by a
majority of state legislatures, the United States Congress, medical
journals, physicians, reporters, even judges, and has never, as far
as I am aware, been used to refer to the D&E procedure. The
number of instances in which "partial birth abortion" has been
equated with the breech extraction form of intact D&E
(otherwise known as "D&X") 10 and explicitly contrasted with
D&E, are numerous. I will limit myself to just a few
examples.

															First, numerous medical authorities have equated "partial birth
abortion" with D&X. The AMA has done so and has recognized that
the procedure is "different from other destructive abortion
techniques because the fetus ... is killed outside of the
womb." AMA Board of Trustees Factsheet on H. R. 1122 (June 1997),
in App. to Brief for Association of American Physicians and
Surgeons et al. as Amici Curiae 1. Medical literature has
also equated "partial birth abortion" with D&X as distinguished
from D&E. See Gynecologic, Obstetric, and Related Surgery, at
1043; Sprang & Neerhof, Rationale for Banning Abortions Late in
Pregnancy, 280 JAMA 744 (Aug. 26,1998); Bopp & Cook, Partial
Birth Abortion: The Final Frontier of Abortion Jurisprudence, 14
Issues in Law and Medicine 3 (1998). Physicians have equated
"partial birth abortion" with D&X. See Planned
Parenthood v. Doyle, 44 F. Supp. 2d 975, 999 (WD Wis.
1999) (citing testimony); Richmond Medical Center for Women v. Gil- 9 It is certainly true that an undefined term must be construed
in accordance with its ordinary and plain meaning. FDIC v. Meyer, 510 U.
S. 471 , 476 (1994). But this does not mean that the ordinary
and plain meaning of a term is wholly irrelevant when that term is
defined.

															10 As noted, see n. 5, supra, there is no consensus
regarding which of these terms is appropriate to describe the
procedure. I assume, as the majority does, that the terms are, for
purposes here, interchangeable. 994 more, 55 F. Supp. 2d 441, 455 (ED Va. 1999) (citing
testimony). Even respondent's expert, Dr. Phillip Stubblefield,
acknowledged that breech extraction intact D&E is referred to
in the lay press as "partial birth abortion." App.271.

															Second, the lower courts have repeatedly acknowledged that
"partial birth abortion" is commonly understood to mean D&X.
See Little Rock Family Planning Services v. Jegley, 192 F.3d
794 , 795 (CA8 1999) ("The term 'partialbirth abortion,'
... is commonly understood to refer to a particular procedure also
known as intact dilation and extraction"); Planned Parenthood of
Greater Iowa, Inc. v. Miller, 195
F.3d 386 , 387 (CA8 1999) ("The [Iowa] Act prohibits
'partial-birth abortion,' a term commonly understood to refer to a
procedure called a dilation and extraction (D&X)"). The
District Court in this case noted that "[p]artial-birth abortions"
are "known medically as intact dilation and extraction or D&X."
11 F. Supp. 2d, at 1121, n. 26. Even the majority notes that
"partial birth abortion" is a term "ordinarily associated with the
D&X procedure." Ante, at 942.

															Third, the term "partial birth abortion" has been used in state
legislation on 28 occasions and by Congress twice. The term
"partial birth abortion" was adopted by Congress in both 1995 and
1997 in two separate pieces of legislation prohibiting the
procedure.ll In considering the legislation,

															11 Congressional legislation prohibiting the procedure was first
introduced in June 1995, with the introduction of the Partial Birth
Abortion Ban Act, H. R. 1833. This measure, which was sponsored by
165 individual House Members, passed both Houses by wide margins,
141 Congo Rec. 35892 (1995); 142 Congo Rec. 31169 (1996), but was
vetoed by President Clinton, see id., at 7467. The House
voted to override the veto on September 19, 1996, see id., at 23851; however, the Senate failed to override by a margin of 13
votes, see id., at 25829. In the next Congress, 181
individual House cosponsors reintroduced the Partial Birth Abortion
Ban Act as H. R. 929, which was later replaced in the House with H.
R. 1122. See H. R. 1122, 105th Cong., 1st Sess. (1997). The House
and Senate again adopted the legislation, as amended, by wide
margins. See 143 995 Congress conducted numerous hearings and debates on the issue,
which repeatedly described "partial birth abortion" as a procedure
distinct from D&E. The Congressional Record contained numerous
references to Dr. Haskell's procedure. See, e. g., H.
R. 1833 Hearing 3, 17,52, 77; S. 6 and H. R. 929 Joint Hearing 45.
Since that time, debates have taken place in state legislatures
across the country, 30 of which have voted to prohibit the
procedure. With only two exceptions, the legislatures that voted to
ban the procedure referred to it as "partial birth abortion." 12
These debates also referred to Dr. Haskell's procedure as D&X.
Both the evidence before the legislators and the legislators
themselves equated "partial birth abortion" with D&X. The fact
that 28 States adopted legislation banning "partial birth
abortion," defined it in a way similar or identical to Nebraska's
definition,13 and,

															Congo Rec. H1230 (Mar. 20, 1997); id., at S4715 (May 20,
1997). President Clinton again vetoed the bill. See id., at
H8891 (Oct. 10, 1997). Again, the veto override passed in the House
and fell short in the Senate. See 144 Congo Rec. H6213 (July 23,
1998); id., at S10564 (Sept. 18, 1998).

															12 Consistent with the practice of Dr. Haskell (an Ohio
practitioner), Ohio referred to the procedure as "dilation and
extraction," defined as "the termination of a human pregnancy by
purposely inserting a suction device into the skull of a fetus to
remove the brain." Ohio Rev. Code Ann. § 2919.15(A) (1997).
Missouri refers to the killing of a "partially-born" infant as
"infanticide." Mo. Stat. Ann. § 565.300 (Vernon Supp. 2000).

															13 For the most part, these States defined the term "partial
birth abortion" using language similar to that in the 1995 proposed
congressional legislation, that is "an abortion in which the person
performing the abortion partially vaginally delivers a living fetus
before killing the fetus and completing the delivery." See H. R.
1833 Hearing 210. See, e. g., Alaska Stat. Ann. §
18.16.050 (1998); Ariz. Rev. Stat. Ann. § 13-3603.01 (Supp. 1999);
Ark. Code Ann. § 5-61-202 (1997); Fla. Stat. § 390.011 (Supp.
2000); Ill. Compo Stat., ch. 720, § 513/5 (1999); Ind. Code Ann. §
16-18-2-267.5 (West Supp. 1999); Mich. Compo Laws Ann. § 333.
17016(5)(c) (West Supp. 2000); Miss. Code Ann. §41-41-73(2)(a)
(Supp. 1998); S. C. Code Ann. §4441-85(A)(1) (1999 Cum. Supp.).
Other States, including Nebraska, see Neb. Rev. Stat. Ann. §28-326
(Supp. 1999), defined "partial-birth abortion" using language
similar to that used in the 1997 proposed congressional 996 in doing so, repeatedly referred to the breech extraction form
of intact D&E and repeatedly distinguished it from ordinary
D&E, makes it inconceivable that the term "partial birth
abortion" could reasonably be interpreted to mean D&E.

															C

															Were there any doubt remaining whether the statute could apply
to a D&E procedure, that doubt is no ground for invalidating
the statute. Rather, we are bound to first consider whether a
construction of the statute is fairly possible that would avoid the
constitutional question. Erznoznik v. Jacksonville, 422 U. S. 205 ,
216 (1975) ("[A] state statute should not be deemed facially
invalid unless it is not readily subject to a narrowing
construction by the state courts"); Frisby v. Schultz, 487
U. S. 474 , 482 (1988) ("The precise scope of the ban is not
further described within the text of the ordinance, but in our view
the ordinance is readily subject to a narrowing construction that
avoids constitutional difficulties"). This principle is, as JUSTICE
O'CONNOR has said, so "wellestablished" that failure to apply is
"plain error." Id., at 483. Although our interpretation of a
Nebraska law is of course not binding on Nebraska courts, it is
clear, as Erznoznik and Frisby demonstrate, that,
absent a conflicting interpretation by Nebraska (and there is none
here), we should, if the text permits, adopt such a
construction.

															legislation, which retained the definition of partial birth
abortion used in the 1995 bill, that is "an abortion in which the
person performing the abortion partially vaginally delivers a
living fetus before killing the fetus and completing the delivery,"
but further defined that phrase to mean "deliberately and
intentionally delivers into the vagina a living fetus, or a
substantial portion there of, for the purpose of performing a
procedure the physician knows will kill the fetus, and kills the
fetus." See Partial Birth Abortion Ban Act of 1997, H. R. 1122,
105th Cong., 1st Sess. (1997). See, e. g., Idaho Code
§ 18-613(a) (Supp. 1999); Iowa Code Ann. § 707.8A(1)(c) (Supp.
1999); N. J. Stat. Ann. § 2A:65A-6(e) (West Supp. 2000); Okla.
Stat. Ann., Tit. 21, § 684 (Supp. 2000); R. I. Gen. Laws § 234.12-1
(Supp. 1999); Tenn. Code Ann. § 39-15-209(a)(1) (1997). 997 The majority contends that application of the Nebraska statute
to D&E would pose constitutional difficulties because it would
eliminate the most common form of secondtrimester abortions. To the
extent that the majority's contention is true, there is no doubt
that the Nebraska statute is susceptible of a narrowing
construction by Nebraska courts that would preserve a physicians'
ability to perform D&E. See State v. Carpenter, 250 Neb. 427, 434, 551 N. W. 2d 518, 524 (1996) ("A penal statute
must be construed so as to meet constitutional requirements if such
can reasonably be done"). For example, the statute requires that
the physician "deliberately and intentionally delive[r] into the
vagina a living unborn child, or a substantial portion thereof,"
before performing a death-causing procedure. The term "substantial
portion" is susceptible to a narrowing construction that would
exclude the D&E procedure. One definition of the word
"substantial" is "being largely but not wholly that which is
specified." Webster's Ninth New Collegiate Dictionary, at 1176. See Pierce v. Underwood, 487 U. S. 552 , 564 (1988)
(describing different meanings of the term "substantial"). In other
words, "substantial" can mean "almost all" of the thing
denominated. If nothing else, a court could construe the statute to
require that the fetus be "largely, but not wholly," delivered out
of the uterus before the physician performs a procedure that he
knows will kill the unborn child. Or, as I have discussed, a court
could (and should) construe "for the purpose of performing a
procedure" to mean "for the purpose of performing a separate
procedure."

															III

															The majority and JUSTICE O'CONNOR reject the plain language of
the statutory definition, refuse to read that definition in light
of the statutory reference to "partial birth abortion," and ignore
the doctrine of constitutional avoidance. In so doing, they offer
scant statutory analysis of their own. See ante, at 938-940
(majority opinion); cf. ante, at 940-945 998 (majority opinion); ante, at 948-949 (O'CONNOR, J.,
concurring). In their brief analyses, the majority and JUSTICE
O'CONNOR disregard all of the statutory language except for the
final definitional sentence, thereby violating the fundamental
canon of construction that statutes are to be read as a whole. United States v. Morton, 467 U. S., at 828 ("We do
not ... construe statutory phrases in isolation; we read statutes
as a whole. Thus, the words [in question] must be read in light of
the immediately following phrase") (footnote omitted)); United
States v. Heirs of Boisdore, 8 How. 113, 122 (1849) ("In
expounding a statute, we must not be guided by a single sentence or
member of a sentence, but look to the provisions of the whole law,
and to its object and policy"); Gustafson v. Alloyd
Co., 513 U. S.
561 , 575 (1995) ("[A] word is known by the company it
keeps").14 In lieu of analyzing the statute as a whole, the
majority and JUSTICE O'CONNOR

															14 The majority argues that its approach is supported by Meese v. Keene, 481 U. S. 465 , 487
(1987), in which the Court stated that "the statutory definition of
[a] term excludes unstated meanings of that term." But this case
provides no support for the approach adopted by the majority and
JUSTICE O'CONNOR. In Meese, the Court addressed a statute
that used the term "political propaganda." Id., at 470. The
Court noted that there were two commonly understood meanings to the
term "political propaganda," id., at 477, and, not
surprisingly, chose the definition that was most consistent with
the statutory definition, id., at 485. Nowhere did the Court
suggest that, because "political propaganda" was defined in the
statute, the commonly understood meanings of that term were
irrelevant. Indeed, a significant portion of the Court's opinion
was devoted to describing the effect of Congress' use of that term. Id., at 477-479, 483-484. So too, Colautti v. Franklin, 439
U. S. 379 , 392-393, n. 10 (1979), and Western Union
Telegraph Co. v. Lenroot, 323 U. S. 490 (1945),
support the proposition that when there are two possible
interpretations of a term, and only one comports with the statutory
definition, the term should not be read to include the unstated
meaning. But here, there is only one possible interpretation of
"partial birth abortion"-the majority can cite no authority using
that term to describe D&E-and so there is no justification for
the majority's willingness to entirely disregard the statute's use
of that term. 999 offer five principal arguments for their interpretation of the
statute. I will address them in turn.

															First, the majority appears to accept, if only obliquely, an
argument made by respondent: If the term "partial birth abortion"
refers to only the breech extraction form of intact D&E, or
D&X, the Nebraska Legislature should have used the medical
nomenclature. See ante, at 943 (noting that the Nebraska
Legislature rejected an amendment that would replace "partial birth
abortion" with "dilation and extraction"); Brief for Respondent
4-5, 24.

															There is, of course, no requirement that a legislature use
terminology accepted by the medical community. A legislature could,
no doubt, draft a statute using the term "heart attack" even if the
medical community preferred "myocardial infarction." Legislatures,
in fact, sometimes use medical terms in ways that conflict with
their clinical definitions, see, e. g., Barber v. Director, 43 F.3d
899 , 901 (CA4 1995) (noting that the medical definition
of "pneumoconiosis" is only a subset of the afflictions that fall
within the definition of "pneumoconiosis" in the Black Lung Act), a
practice that is unremarkable so long as the legal term is
adequately defined. We have never, until today, suggested that
legislature may only use words accepted by every individual
physician. Rather, "we have traditionally left to legislators the
task of defining terms of a medical nature that have legal
significance." Kansas v. Hendricks, 521 U. S. 346 , 359
(1997). And we have noted that "[o]ften, those definitions do not
fit precisely with the definitions employed by the medical
community." Ibid. Further, it is simply not true that the many legislatures,
including Nebraska's, that prohibited "partial birth abortion"
chose to use a term known only in the vernacular in place of a term
with an accepted clinical meaning. When the Partial-Birth Abortion
Ban Act of 1995 was introduced in Congress, the term "dilation and
extraction" did not appear in any medical dictionary. See, e. g., Dorland's Illustrated 1000 Medical Dictionary 470 (28th ed. 1994); Stedman's Medical
Dictionary, at 485; Miller-Keane Encyclopedia & Dictionary of
Medicine, Nursing, & Allied Health 460 (6th ed. 1997); The
Sloane-Dorland Annotated Medical-Legal Dictionary 204 (1987); 1.
Dox, J. Melloni, & G. Eisher, The HarperCollins Illustrated
Medical Dictionary 131 (1993). The term did not appear in
descriptions of abortion methods in leading medical textbooks. See, e. g., G. Cunningham et aI., Williams Obstetrics
579-605 (20th ed. 1997); Obstetrics: Normal & Problem
Pregnancies, at 1249-1279; W. Hern, Abortion Practice (1990).
Abortion reference books also omitted any reference to the term.
See, e. g., Modern Methods of Inducing Abortion (D.
Baird, D. Grimes, & P. Van Look eds. 1995); E. Glick, Surgical
Abortion (1998).15

															Not only did D&X have no medical meaning at the time, but
the term is ambiguous on its face. "Dilation and extraction" would,
on its face, accurately describe any procedure in which the woman
is "dilated" and the fetus "extracted," including D&E. See supra, at 984-985. In contrast, "partial birth abortion" has
the advantage of faithfully describing the procedure the
legislature meant to address because the fact that a fetus is
"partially born" during the procedure is indisputable. The term
"partial birth abortion" is completely accurate and descriptive,
which is perhaps the reason why the majority finds it
objectionable. Only a desire to find fault at any cost could
explain the Court's willingness to penalize the Nebraska
Legislature for failing to replace a

															15 Nor, for that matter, did the terms "intact dilation and
extraction" or "intact dilation and evacuation" appear in textbooks
or medical dictionaries. See supra, at 999 and this page. In
fact, respondent's preferred term "intact D&E" would compound,
rather than remedy, any confusion regarding the statute's meaning.
As is evident from the majority opinion, there is no consensus on
what this term means. Compare ante, at 927 (describing
"intact D&E" to refer to both breech and vertex presentation
procedures), with App. 6 (testimony of Dr. Henshaw) (using "intact
D&E" to mean only breech procedure), with id., at 275
(testimony of Dr. Stubblefield) (using "intact D&E" to refer to
delivery of fetus that has died in utero). 1001 descriptive term with a vague one. There is, therefore, nothing
to the majority's argument that the Nebraska Legislature is at
fault for declining to use the term "dilation and extraction."
16

															Second, the majority faults the Nebraska Legislature for failing
to "track the medical differences between D&E and D&X" and
for failing to "suggest that its application turns on whether a
portion of the fetus' body is drawn into the vagina as part of a
process to extract an intact fetus after collapsing the head as
opposed to a process that would dismember the fetus." Ante, at 939. I have already explained why the Nebraska statute reflects
the medical differences between D&X and D&E. To the extent
the majority means that the Nebraska Legislature should have
"tracked the medical differences" by adopting one of the informal
definitions of D&X, this argument is without merit; none of
these definitions would have been effective to accomplish the
State's purpose of preventing abortions of partially born fetuses.
Take, for example, ACOG's informal definition of the term "intact
D&X." According to ACOG, an "intact D&X" consists of the
following four steps: (1) deliberate dilation of

															16 The fact that the statutory term "partial birth abortion" may
express a political or moral judgment, whereas "dilation and
extraction" does not, is irrelevant. It is certainly true that
technical terms are frequently empty of normative content. (Of
course, the decision to use a technical term can itself be
normative. See ante, passim (majority opinion)). But, so
long as statutory terms are adequately defined, there is no
requirement that Congress or state legislatures draft statutes
using morally agnostic terminology. See, e. g., 18 U.
S. C. § 922(v) (making it unlawful to "manufacture, transfer, or
possess a semiautomatic assault weapon"); Kobayashi & Olson et
al., In re 101 California Street: A Legal and Economic
Analysis of Strict Liability for the Manufacture and Sale of
"Assault Weapons," 8 Stan. L. & Pol'y Rev. 41, 43 (1997)
("Prior to 1989, the term 'assault weapon' did not exist in the
lexicon of firearms. It is a political term, developed by anti-gun
publicists to expand the category of 'assault rifles' so as to
allow an attack on as many additional firearms as possible on the
basis of undefined 'evil' appearance"). See also Meese, 481
U. S., at 484-485. 1002 the cervix, usually over a sequence of days; (2) instrumental
conversion of the fetus to a footling breach; (3) breech extraction
of the body excepting the head; and (4) partial evacuation of the
intracranial contents of a living fetus to effect vaginal delivery
of a dead but otherwise intact fetus. App. 599-600 (AGOG Executive
Board, Statement on Intact Dilation and Extraction (Jan. 12,
1997)). AGOG emphasizes that "unless all four elements are present
in sequence, the procedure is not an intact D&X." Id., at 600. Had Nebraska adopted a statute prohibiting "intact
D&X," and defined it along the lines of the AGOG definition,
physicians attempting to perform abortions on partially born
fetuses could have easily evaded the statute. Any doctor wishing to
perform a partial birth abortion procedure could simply avoid
liability under such a statute by performing the procedure, as
respondent does, only when the fetus is presented feet first,
thereby avoiding the necessity of "conversion of the fetus to a
footling breech." Id., at 599. Or, a doctor could convert
the fetus without instruments. Or, the doctor could cause the
fetus' death before "partial evacuation of the intracranial
contents," id., at 600, by plunging scissors into the fetus'
heart, for example. A doctor could even attempt to evade the
statute by chopping off two fetal toes prior to completing
delivery, preventing the State from arguing that the fetus was
"otherwise intact." Presumably, however, Nebraska, and the many
other legislative bodies that adopted partial birth abortion bans,
were not concerned with whether death was inflicted by injury to
the brain or the heart, whether the fetus was converted with or
without instruments, or whether the fetus died with its toes
attached. These legislative bodies were, I presume, concerned with
whether the child was partially born before the physician caused
its death. The legislatures' evident concern was with permitting a
procedure that resembles infanticide and threatens to dehumanize
the fetus. They, therefore, presumably declined to adopt a 1003 ban only on "intact D&X," as defined by ACOG, because it
would have been ineffective to that purpose. Again, the majority is
faulting Nebraska for a legitimate legislative calculation.

															Third, the majority and JUSTICE O'CONNOR argue that this Court
generally defers to lower federal courts' interpretations of state
law. Ante, at 940 (majority opinion); ante, at 949
(O'CONNOR, J., concurring). However, a decision drafted by JUSTICE
O'CONNOR, which she inexplicably fails to discuss, Frisby v. Schultz, 487
U. S. 474 (1988), makes clear why deference is inappropriate
here. As JUSTICE O'CONNOR explained in that case: "[WJhile we ordinarily defer to lower court constructions of
state statutes, we do not invariably do so. We are particularly
reluctant to defer when the lower courts have fallen into plain
error, which is precisely the situation presented here. To the
extent they endorsed a broad reading of the ordinance, the lower
courts ran afoul of the well-established principle that statutes
will be interpreted to avoid constitutional difficulties." Id., at 483 (citations omitted). Frisby, then, identifies exactly why the lower courts'
opinions here are not entitled to deference: The lower courts
failed to identify the narrower construction that, consistent with
the text, would avoid any constitutional difficulties.

															Fourth, the majority speculates that some Nebraska prosecutor
may attempt to stretch the statute to apply it to D&E. But a
state statute is not unconstitutional on its face merely because we
can imagine an aggressive prosecutor who would attempt an overly
aggressive application of the statute. We have noted that" '[w]ords
inevitably contain germs of uncertainty.'" Broadrick v. Oklahoma, 413
U. S. 601 , 608 (1973). We do not give statutes the broadest
definition imaginable. Rather, we ask whether "the ordinary 1004 person exercising ordinary common sense can sufficiently
understand and comply with [the statute]." Ibid. (quoting Civil Service Comm'n v. Letter Carriers, 413 U. S. 548 , 579
(1973)). While a creative legal mind might be able to stretch the
plain language of the Nebraska statute to apply to D&E,
"citizens who desire to obey the statute will have no difficulty in
understanding it." Colten v. Kentucky, 407 U. S. 104 , 110 (1972)
(internal quotation marks omitted).

															Finally, the majority discusses at some length the reasons it
will not defer to the interpretation of the statute proffered by
the Nebraska Attorney General, despite the Attorney General's
repeated representations to this Court that his State will not
apply the partial birth abortion statute to D&E. See Brief for
Petitioners 11-13; Tr. of Oral Arg. lOll. The fact that the Court
declines to defer to the interpretation of the Attorney General is
not, however, a reason to give the statute a contrary
representation. Even without according the Attorney General's view
any particular respect, we should agree with his interpretation
because it is undoubtedly the correct one. Moreover, JUSTICE
O'CONNOR has noted that the Court should adopt a narrow
interpretation of a state statute when it is supported by the
principle that statutes will be interpreted to avoid constitutional
difficulties as well as by "the representations of counsel ... at
oral argument." Frisby v. Schultz, supra, at 483.
Such an approach is particularly appropriate in this case because,
as the majority notes, Nebraska courts accord the Nebraska Attorney
General's interpretations of state statutes "substantial weight."
See State v. Coffman, 213 Neb. 560, 561, 330 N. W. 2d
727, 728 (1983). Therefore, any renegade prosecutor bringing
criminal charges against a physician for performing a D&E would
find himself confronted with a contrary interpretation of the
statute by the Nebraska Attorney General, and, I assume, a judge
who both possessed common 1005 sense and was aware of the rule of lenity. See State v. White, 254 Neb. 566, 575, 577 N. W. 2d 741, 747 (1998).17 IV

															Having resolved that Nebraska's partial birth abortion statute
permits doctors to perform D&E abortions, the question remains
whether a State can constitutionally prohibit the partial birth
abortion procedure without a health exception. Although the
majority and JUSTICE O'CONNOR purport to rely on the standard
articulated in the Casey plurality in concluding that a
State may not, they in fact disregard it entirely.

															A

															Though JUSTICES O'CONNOR, KENNEDY, and SOUTER declined in Casey, on the ground of stare decisis, to reconsider
whether abortion enjoys any constitutional protection, 505 U. S.,
at 844-846, 854-869 (majority opinion); id., at 871
(plurality opinion), Casey professed to be, in part, a
repudiation of Roe and its progeny. The Casey plurality expressly noted that prior case law had undervalued the
State's interest in potential life, 505 U. S., at 875-876, and had
invalidated regulations of abortion that "in no real sense deprived
women of the ultimate decision," id., at 875. See id., at 871 ("Roe v. Wade speaks with clarity
in establishing ... the State's 'important and legitimate interest
in potential life.' That por-

															17The majority relies on JUSTICE SCALIA'S observation in Crandon v. United States, 494 U. S. 152 (1990),
that "we have never thought that the interpretation of those
charged with prosecuting criminal statutes is entitled to
deference." Id., at 177. But JUSTICE SCALIA was commenting
on the United States Attorney General's overly broad interpretation
of a federal statute, deference to which, as he said, would "turn
the normal construction of criminal statutes upside-down, replacing
the doctrine of lenity with a doctrine of severity." Id., at
178. Here, the Nebraska Attorney General has adopted a narrow view of a criminal statute, one that comports with
the rule of lenity (not to mention the statute's plain
meaning). 1006 tion of the decision in Roe has been given too little
acknowledgment" (citation omitted)). The plurality repeatedly
recognized the States' weighty interest in this area. See id., at 877 ("State ... may express profound respect for the
life of the unborn"); id., at 878 ("the State's profound
interest in potential life"); id., at 850 (majority opinion)
("profound moral and spiritual implications of terminating a
pregnancy, even in its earliest stage"). And, the plurality
expressed repeatedly the States' legitimate role in regulating
abortion procedures. See id., at 876 ("The very notion that
the State has a substantial interest in potential life leads to the
conclusion that not all regulations must be deemed unwarranted"); id., at 875 ("Not all governmental intrusion [with abortion]
is of necessity unwarranted"). According to the plurality:

															"The fact that a law which serves a valid purpose, one not
designed to strike at the right itself, has the incidental effect
of making it more difficult or more expensive to procure an
abortion cannot be enough to invalidate it." Id., at
874.

															The Casey plurality therefore adopted the standard: "Only
where state regulation imposes an undue burden on a woman's ability
to make this decision does the power of the State reach into the
heart of the liberty protected by the Due Process Clause." Ibid. A regulation imposes an "undue burden" only if it "has
the effect of placing a substantial obstacle in the path of a
woman's choice." Id., at 877.

															B

															There is no question that the State of Nebraska has a valid
interest-one not designed to strike at the right itself-in
prohibiting partial birth abortion. Casey itself noted that
States may "express profound respect for the life of the unborn." Ibid. States may, without a doubt, express this profound
respect by prohibiting a procedure that approaches infanticide, and
thereby dehumanizes the fetus and trivializes human life. The AMA
has recognized that this procedure is "ethically different from
other destructive abortion 1007 techniques because the fetus, normally twenty weeks or longer in
gestation, is killed outside the womb. The 'partial birth'
gives the fetus an autonomy which separates it from the right of
the woman to choose treatments for her own body." AMA Board of
Trustees Factsheet on H. R. 1122 (June 1997), in App. to Brief for
Association of American Physicians and Surgeons et al. as Amici
Curiae 1. Thirty States have concurred with this view.

															Although the description of this procedure set forth above
should be sufficient to demonstrate the resemblance between the
partial birth abortion procedure and infanticide, the testimony of
one nurse who observed a partial birth abortion procedure makes the
point even more vividly: "The baby's little fingers were clasping and unclasping, and his
little feet were kicking. Then the doctor stuck the scissors in the
back of his head, and the baby's arms jerked out, like a startle
reaction, like a flinch, like a baby does when he thinks he is
going to fall. "The doctor opened up the scissors, stuck a highpowered suction
tube into the opening, and sucked the baby's brains out. Now the
baby went completely limp." H. R. 1833 Hearing 18 (statement of
Brenda Pratt Shafer). The question whether States have a legitimate interest in
banning the procedure does not require additional authority. See ante, at 961-964 (KENNEDY, J., dissenting).18 In a civi-

															18 I read the majority opinion to concede, if only implicitly,
that the State has a legitimate interest in banning this
dehumanizing procedure. The threshold question under Casey is whether the abortion regulation serves a legitimate state
interest. 505 U. S.
833 (1992). Only if the statute serves a legitimate state
interest is it necessary to consider whether the regulation imposes
a substantial obstacle to women seeking an abortion. Ibid. The fact that the majority considers whether Nebraska's statute
creates a substantial obstacle suggests that the Members of the
majority other than JUSTICE STEVENS and JUSTICE GINSBURG have
rejected respondent's threshold argument that the statute serves no
legitimate state purpose. 1008 lized society, the answer is too obvious, and the contrary
arguments too offensive, to merit further discussion. But see ante, at 946-947 (STEVENS, J., concurring) (arguing that the
decision of 30 States to ban the partial birth abortion procedure
was "simply irrational" because other forms of abortion were
"equally gruesome"); ante, at 951-952 (GINSBURG, J.,
concurring) (similar ).19

															19 JUSTICE GINSBURG seems to suggest that even if the Nebraska
statute does not impose an undue burden on women seeking abortions,
the statute is unconstitutional because it has the purpose of imposing an undue burden. JUSTICE GINSBURG'S view is,
apparently, that we can presume an unconstitutional purpose because
the regulation is not designed to save any fetus from "destruction"
or protect the health of pregnant women and so must, therefore, be
designed to "chip away at ... Roe." Ante, at 952. This is a
strange claim to make with respect to legislation that was enacted
in 30 individual States and was enacted in Nebraska by a vote of 45
to 1, Nebraska Legislative Journal, 95th Leg., 1st Sess., 2609
(1997). Moreover, in support of her assertion that the Nebraska
Legislature acted with an unconstitutional purpose, JUSTICE
GINSBURG is apparently unable to muster a single shred of evidence
that the Nebraska legislation was enacted to prevent women from
obtaining abortions (a purpose to which it would be entirely
ineffective), let alone the kind of persuasive proof we would
require before concluding that a legislature acted with an
unconstitutional intent. In fact, as far as I can tell, JUSTICE
GINSBURG'S views regarding the motives of the Nebraska Legislature
derive from the views of a dissenting Court of Appeals judge
discussing the motives of legislators of other States. JUSTICE
GINSBURG'S presumption is, in addition, squarely inconsistent with Casey, which stated that States may enact legislation to
"express profound respect for the life of the unborn," 505 U. S.,
at 877, and with our opinion in Mazurek v. Armstrong, 520 U. S. 968 (1997) (per curiam), in which we stated:

															"[E]ven assuming ... that a legislative purpose to
interfere with the constitutionally protected right to abortion
without the effect of interfering with that right ... could
render the Montana law invalid-there is no basis for finding a
vitiating legislative purpose here. We do not assume
unconstitutional legislative intent even when statutes produce
harmful results, see, e. g., Washington v. Davis, 426 U. S. 229 ,
246 (1976); much less do we assume it when the results are
harmless." Id., at 972 (emphases in original). 1009 C

															The next question, therefore, is whether the Nebraska statute is
unconstitutional because it does not contain an exception that
would allow use of the procedure whenever " '''necessary, in
appropriate medical judgment, for the preservation of the ...
health of the mother."'" Ante, at 930 (majority opinion)
(quoting Casey, 505 U. S., at 879, in turn quoting Roe, 410 U. S., at 164-165) (emphasis deleted). According to
the majority, such a health exception is required here because
there is a "division of opinion among some medical experts over
whether D&X is generally safer [than D&E], and an absence
of controlled medical studies that would help answer these medical
questions." Ante, at 936937. In other words, unless a State
can conclusively establish that an abortion procedure is no safer
than other procedures, the State cannot regulate that procedure
without including a health exception. JUSTICE O'CONNOR agrees. Ante, at 947-948 (concurring opinion). The rule set forth by
the majority and JUSTICE O'CONNOR dramatically expands on our prior
abortion cases and threatens to undo any state regulation of
abortion procedures.

															The majority and JUSTICE O'CONNOR suggest that their rule is
dictated by a straightforward application of Roe and Casey. Ante, at 929-930 (majority opinion); ante, at
947-948 (O'CONNOR, J., concurring). But that is simply not true. In Roe and Casey, the Court stated that the State may
"regulate, and even proscribe, abortion except where it is
necessary, in appropriate medical judgment, for the preservation of
the life or health of the mother." Roe, supra, at 165; Casey, 505 U. S., at 879. Casey said that a health
exception must be available if "continuing her pregnancy would constitute a threat" to the woman. Id., at 880
(majority opinion) (emphasis added). Under these cases, if a State
seeks to prohibit abortion, even if only temporarily or under
particular circumstances, as Casey says that it may, id., at 879 (plu- 1010 rality opinion), the State must make an exception for cases in
which the life or health of the mother is endangered by continuing
the pregnancy. These cases addressed only the situation in which a
woman must obtain an abortion because of some threat to her health
from continued pregnancy. But Roe and Casey say
nothing at all about cases in which a physician considers one
prohibited method of abortion to be preferable to permissible
methods. Today's majority and JusTICE O'CONNOR twist Roe and Casey to apply to the situation in which a woman desires-for
whatever reason-an abortion and wishes to obtain the abortion by
some particular method. See ante, at 929-931 (majority
opinion); ante, at 947-948 (concurring opinion). In other
words, the majority and JUSTICE O'CONNOR fail to distinguish
between cases in which health concerns require a woman to obtain an
abortion and cases in which health concerns cause a woman who
desires an abortion (for whatever reason) to prefer one method over
another.

															It is clear that the Court's understanding of when a health
exception is required is not mandated by our prior cases. In fact,
we have, post-Casey, approved regulations of methods of
conducting abortion despite the lack of a health exception. Mazurek v. Armstrong, 520 U. S. 968 , 971 (1997) (per curiam) (reversing Court of Appeals holding that
plaintiffs challenging requirement that only physicians perform
abortions had a "'fair chance of success' "); id., at 979
(STEVENS, J., dissenting) (arguing that the regulation was designed
to make abortion more difficult). And one can think of vast bodies
of law regulating abortion that are valid, one would hope, despite
the lack of health exceptions. For example, physicians are
presumably prohibited from using abortifacients that have not been
approved by the Food and Drug Administration even if some
physicians reasonably believe 1011 that these abortifacients would be safer for women than existing
abortifacients.2o

															The majority effectively concedes that Casey provides no
support for its broad health exception rule by relying on pre-Casey authority, see ante, at 931, including a
case that was specifically disapproved of in Casey for
giving too little weight to the State's interest in fetal life. See Casey, supra, at 869, 882 (overruling the parts of Thornburgh v. American College of Obstetricians and
Gynecologists, 476 U. S. 747 (1986),
that were "inconsistent with Roe's statement that the State
has a legitimate interest in promoting the life or potentiallife of
the unborn," 505 U. S., at 870); id., at 893 (majority
opinion) (relying on Thornburgh, supra, at 783 (Burger, C.
J., dissenting), for the proposition that the Court was expanding
on Roe in that case). Indeed, JUSTICE O'CONNOR, who joins
the Court's opinion, was on the Court for Thornburgh and was
in dissent, arguing that, under the undue-burden standard, the
statute at issue was constitutional. See 476 U. S., at 828-832
(arguing that the challenged state statute was not "unduly
burdensome"). The majority's resort to this case proves my point
that the holding today assumes that the standard set forth in the Casey joint opinion is no longer governing.

															And even if I were to assume that the pre-Casey standards
govern, the cases cited by the majority provide no support for the
proposition that the partial birth abortion ban must

															20 As I discuss below, the only question after Casey is
whether a ban on partial birth abortion without a health exception
imposes an "undue burden" on a woman seeking an abortion, meaning
that it creates a "substantial obstacle" for the woman. I assume
that the Court does not discuss the health risks with respect to
undue burden, and instead suggests that health risks are relevant
to the necessity of a health exception, because a marginal increase
in safety risk for some women is clearly not an undue burden within
the meaning of Casey. At bottom, the majority is using the
health exception language to water down Casey's undue-burden
standard. 1012 include a health exception because some doctors believe that
partial birth abortion is safer. In Thornburgh, Danforth, and Doe, the Court addressed health exceptions for cases in
which continued pregnancy would pose a risk to the woman. Thornburgh, supra, at 770; Planned Parenthood of Central
Mo. v. Danforth, 428 U. S. 52 (1976); Doe v. Bolton, 410 U. S., at 197. And in Colautti v. Franklin, 439 U. S. 379 (1979), the
Court explicitly declined to address whether a State can
constitutionally require a tradeoff between the woman's health and
that of the fetus. The broad rule articulated by the majority and
by JUSTICE O'CONNOR are unprecedented expansions of this Court's
already expansive pre-Casey jurisprudence.

															As if this state of affairs were not bad enough, the majority
expands the health exception rule articulated in Casey in
one additional and equally pernicious way. Although Roe and Casey mandated a health exception for cases in which
abortion is "necessary" for a woman's health, the majority
concludes that a procedure is "necessary" if it has any comparative
health benefits. Ante, at 937. In other words, according to
the majority, so long as a doctor can point to support in the
profession for his (or the woman's) preferred procedure, it is
"necessary" and the physician is entitled to perform it. Ibid. See also ante, at 952 (GINSBURG, J.,
concurring) (arguing that a State cannot constitutionally "sto[p] a
woman from choosing the procedure her doctor 'reasonably believes'"
is in her best interest). But such a health exception requirement
eviscerates Casey's undue-burden standard and imposes
unfettered abortion on demand. The exception entirely swallows the
rule. In effect, no regulation of abortion procedures is permitted
because there will always be some support for a procedure
and there will always be some doctors who conclude that the
procedure is preferable. If Nebraska reenacts its partial birth
abortion ban with a health exception, the State will not be able to
prevent physicians like Dr. Carhart from using partial birth
abortion as a routine abortion procedure. This Court has now
expressed 1013 its own conclusion that there is "highly plausible" support for
the view that partial birth abortion is safer, which, in the
majority's view, means that the procedure is therefore "necessary." Ante, at 937. Any doctor who wishes to perform such a
procedure under the new statute will be able to do so with
impunity. Therefore, JUSTICE O'CONNOR'S assurance that the
constitutional failings of Nebraska's statute can be easily fixed, ante, at 950-951, is illusory. The majority's insistence on
a health exception is a fig leaf barely covering its hostility to
any abortion regulation by the States-a hostility that Casey purported to rejectP

															D

															The majority assiduously avoids addressing the actual standard articulated in Casey-whether prohibiting partial
birth abortion without a health exception poses a substantial
obstacle to obtaining an abortion. 505 U. S., at 877. And for good
reason: Such an obstacle does not exist. There are two essential
reasons why the Court cannot identify a substantial obstacle.
First, the Court cannot identify any real, much less substantial,
barrier to any woman's ability to obtain an abortion. And second,
the Court cannot demonstrate that any such obstacle would affect a
sufficient number of women to justify invalidating the statute on
its face.

															1

															The Casey joint opinion makes clear that the Court should
not strike down state regulations of abortion based on the

															21 The majority's conclusion that health exceptions are required
whenever there is any support for use of a procedure is
particularly troubling because the majority does not indicate
whether an exception for physical health only is required, or
whether the exception would have to account for "all
factors-physical, emotional, psychological, familial, and the
woman's age-relevant to the well being of the patient." Doe v. Bolton, 410 U. S. 179, 192 (1973). See also Voinovich v. Women's Medical Professional Corp., 523
U. S. 1036, 1037 (1998) (THOMAS, J., joined by REHNQUIST, C. J.,
and SCALIA, J., dissenting from denial of certiorari). 1014 fact that some women might face a marginally higher health risk
from the regulation. In Casey, the Court upheld a 24hour
waiting period even though the Court credited evidence that for
some women the delay would, in practice, be much longer than 24
hours, and even though it was undisputed that any delay in
obtaining an abortion would impose additional health risks. Id., at 887; id., at 937 (Blackmun, J., concurring in
part, concurring in judgment in part, and dissenting in part) ("The
District Court found that the mandatory 24-hour delay could lead to
delays in excess of 24 hours, thus increasing health risks").
Although some women would be able to avoid the waiting period
because of a "medical emergency," the medical emergency exception
in the statute was limited to those women for whom delay would
create "serious risk of substantial and irreversible impairment of
a major bodily function." Id., at 902 (appendix to joint
opinion) (internal quotation marks omitted). Without question,
there were women for whom the regulation would impose some
additional health risk who would not fall within the medical
emergency exception. The Court concluded, despite the certainty of
this increased risk, that there was no showing that the burden on
any of the women was substantial. Id., at 887.

															The only case in which this Court has overturned a State's
attempt to prohibit a particular form of abortion also demonstrates
that a marginal increase in health risks is not sufficient to
create an undue burden. In Planned Parenthood of Central Mo. v. Danforth, 428 U. S. 52 (1976), the
Court struck down a state regulation because the State had outlawed
the method of abortion used in 70% of abortions and because
alternative methods were, the Court emphasized, "significantly more
dangerous and critical" than the prohibited method. Id., at
76.

															Like the Casey 24-hour waiting period, and in contrast to
the situation in Danforth, any increased health risk to
women imposed by the partial birth abortion ban is minimal 1015 at most. Of the 5.5% of abortions that occur after 15 weeks (the
time after which a partial birth abortion would be possible), the
vast majority are performed with a D&E or induction procedure.
And, for any woman with a vertex presentation fetus, the vertex
presentation form of intact D&E, which presumably shares some
of the health benefits of the partial birth abortion procedure but
is not covered by the Nebraska statute, is available. Of the
remaining womenthat is, those women for whom a partial birth
abortion procedure would be considered and who have a breech
presentation fetus-there is no showing that anyone faces a
significant health risk from the partial birth abortion ban. A
select committee of ACOG "could identify no circumstances under
which this procedure ... would be the only option to save the life
or preserve the health of the woman." App. 600 (ACOG Executive
Board, Statement on Intact Dilation and Extraction (Jan. 12,
1997)). See also Hope Clinic v. Ryan, 195 F.3d
857 , 872 (CA7 1999) (en banc) (" 'There does not appear
to be any identified situation in which intact D&X is the only
appropriate procedure to induce abortion'" (quoting Late Term
Pregnancy Techniques, AMA Policy H-5.982 W. D. Wis. 1999)); Planned Parenthood of Wis. v. Doyle, 44 F. Supp. 2d,
at 980 (citing testimony of Dr. Haskell that "the D&X procedure
is never medically necessary to ... preserve the health of a
woman"), vacated, 195 F.3d
857 (CA7 1999). And, an ad hoc coalition of doctors,
including former Surgeon General Koop, concluded that there are no
medical conditions that require use of the partial birth abortion
procedure to preserve the mother's health. See App.719.

															In fact, there was evidence before the Nebraska Legislature that
partial birth abortion increases health risks relative to
other procedures. During floor debates, a proponent of the Nebraska
legislation read from and cited several articles by physicians
concluding that partial birth abortion procedures are risky. App.
in Nos. 98-3245, 98-3300 (CA8), 1016 p. 812. One doctor testifying before a committee of the Nebraska
Legislature stated that partial birth abortion involves three "very
risky procedures": dilation of the cervix, using instruments
blindly, and conversion of the fetus. App. 721 (quoting testimony
of Paul Hays, M. D.).22

															There was also evidence before Congress that partial birth
abortion "does not meet medical standards set by ACOG nor has it
been adequately proven to be safe nor efficacious." H. R. 1833
Hearing 112 (statement of Nancy G. Romer, M. D.); see id., at 110-111.23 The AMA supported the congressional ban on partial
birth abortion, concluding that the procedure is "not medically
indicated" and "not good medicine." See 143 Congo Rec. S4670 (May
19, 1997) (reprinting a letter from the AMA to Sen. Santorum). And
there was evidence before Congress that there is "certainly no
basis upon which to state the claim that [partial birth abortion]
is a safer or even a preferred procedure." Partial Birth Abortion:
The Truth, S. 6 and H. R. 929 Joint Hearing 123 (statement of
Curtis Cook, M. D.). This same doctor testified that

															22 Use of the procedure may increase the risk of complications,
including cervical incompetence, because it requires greater
dilation of the cervix than other forms of abortion. See Epner,
Jonas, & Seckinger, Late-term Abortion, 280 JAMA 724, 726 (Aug.
26, 1998). Physicians have also suggested that the procedure may
pose a greater risk of infection. See Planned Parenthood of Wis. v. Doyle, 44 F. Supp. 2d 975, 979 (WD Wis.
1999). See also Sprang & Neerhof, Rationale for Banning
Abortions Late in Pregnancy, 280 JAMA 744 (Aug. 26, 1998) ("Intact
D&X poses serious medical risks to the mother").

															23 Nebraska was entitled to rely on testimony and evidence
presented to Congress and to other state legislatures. Cf. Erie v. Pap's A. M., 529 U. S. 277, 296-297 (2000); Renton v. Playtime Theatres, Inc., 475 U. S. 41 , 51 (1986).
At numerous points during the legislative debates, various members
of the Nebraska Legislature made clear that that body was aware of,
and relying on, evidence before Congress and other legislative
bodies. See App. in Nos. 98-3245, 98-3300 (CA8), pp. 846,
852-853, 878879,890-891,912-913. 1017 "partial-birth abortion is an unnecessary, unsteady, and
potentially dangerous procedure," and that "safe alternatives are
in existence." Id., at 122.

															The majority justifies its result by asserting that a
"significant body of medical opinion" supports the view that
partial birth abortion may be a safer abortion procedure. Ante, at 937. I find this assertion puzzling. If there is a
"significant body of medical opinion" supporting this procedure, no
one in the majority has identified it. In fact, it is uncontested
that although this procedure has been used since at least 1992, no
formal studies have compared partial birth abortion with other
procedures. 11 F. Supp. 2d, at 1112 (citing testimony of Dr.
Stubblefield); id., at 1115 (citing testimony of Dr. Boehm);
Epner, Jonas, & Seckinger, Late-term Abortion, 280 JAMA 724
(Aug. 26,1998); Sprang & Neerhof, Rationale for Banning
Abortion Late in Pregnancy, 280 JAMA 744 (Aug. 26, 1998). Cf. Kumho Tire Co. v. Carmichael, 526 U. S. 137 , 149-152
(1999) (observing that the reliability of a scientific technique
may turn on whether the technique can be and has been tested;
whether it has been subjected to peer review and publication; and
whether there is a high rate of error or standards controlling its
operation). The majority's conclusion makes sense only if the
undueburden standard is not whether a "significant body of medical
opinion" supports the result, but rather, as JUSTICE GINSBURG
candidly admits, whether any doctor could reasonably believe
that the partial birth abortion procedure would best protect the
woman. Ante, at 952.

															Moreover, even if I were to assume credible evidence on both
sides of the debate, that fact should resolve the undueburden
question in favor of allowing Nebraska to legislate. Where no one
knows whether a regulation of abortion poses any burden at all, the
burden surely does not amount to a "substantial obstacle." Under Casey, in such a case we should defer to the legislative
judgment. We have said: 1018 "[I]t is precisely where such disagreement exists that
legislatures have been afforded the widest latitude in drafting
such statutes .... [W]hen a legislature undertakes to act in areas
fraught with medical and scientific uncertainties, legislative
options must be especially broad .... " Kansas v. Hendricks, 521 U. S., at 360, n. 3 (internal quotations
marks omitted). In JUSTICE O'CONNOR'S words: "It is ... difficult to believe that this Court, without the
resources available to those bodies entrusted with making
legislative choices, believes itself competent to make these
inquiries and to revise these standards every time the American
College of Obstetricians and Gynecologists (ACOG) or similar group
revises its views about what is and what is not appropriate medical
procedure in this area." Akron v. Akron Center for
Reproductive Health, Inc., 462 U. S., at 456 (dissenting
opinion). See id., at 456, n. 4 ("Irrespective of the difficulty of
the task, legislatures, with their superior factfinding
capabilities, are certainly better able to make the necessary
judgments than are courts"); Webster v. Reproductive
Health Services, 492 U. S., at 519 (plurality opinion) (Court
should not sit as an "ex officio medical board with powers
to approve or disapprove medical and operative practices and
standards throughout the United States (internal quotations marks
omitted)); Jones v. United States, 463 U. S. 354 , 365, n. 13
(1983) ("The lesson we have drawn is not that government may not
act in the face of this [medical] uncertainty, but rather that
courts should pay particular deference to reasonable legislative
judgments"). The Court today disregards these principles and the
clear import of Casey. 2

															Even if I were willing to assume that the partial birth method
of abortion is safer for some small set of women, such 1019 a conclusion would not require invalidating the Act, because
this case comes to us on a facial challenge. The only question
before us is whether respondent has shown that "'no set of
circumstances exists under which the Act would be valid.'" Ohio v. Akron Center for Reproductive Health, 497 U.
S. 502, 514 (1990) (quoting Webster v. Reproductive
Health Services, supra, at 524 (O'CONNOR, J., concurring in
part and concurring in judgment)). Courts may not invalidate on its
face a state statute regulating abortion "based upon a worst-case
analysis that may never occur." 497 U. S., at 514.

															Invalidation of the statute would be improper even assuming that Casey rejected this standard sub silentio (at least
so far as abortion cases are concerned) in favor of a so-called "
'large fraction'" test. See Fargo Women's Health
Organization v. Schafer, 507 U. S. 1013, 1014 (1993)
(O'CONNOR, J., joined by SOUTER, J., concurring) (arguing that the
"no set of circumstances" standard is incompatible with Casey). See also Janklow v. Planned Parenthood,
Sioux Falls Clinic, 517 U. S. 1174, 1177-1179 (1996) (SCALIA,
J., dissenting from denial of certiorari). In Casey, the
Court was presented with a facial challenge to, among other
provisions, a spousal notice requirement. The question, according
to the majority, was whether the spousal notice provision operated
as a "substantial obstacle" to the women "whose conduct it
affects," namely, "married women seeking abortions who do not wish
to notify their husbands of their intentions and who do not qualify
for one of the statutory exceptions to the notice requirement." 505
U. S., at 895. The Court determined that a "large fraction" of the
women in this category were victims of psychological or physical
abuse. Ibid. For this subset of women, according to the
Court, the provision would pose a substantial obstacle to the
ability to obtain an abortion because their husbands could exercise
an effective veto over their decision. Id., at 897.

															None of the opinions supporting the majority so much as mentions
the large fraction standard, undoubtedly because 1020 the Nebraska statute easily survives it. I will assume, for the
sake of discussion, that the category of women whose conduct
Nebraska's partial birth abortion statute might affect includes any
woman who wishes to obtain a safe abortion after 16 weeks'
gestation. I will also assume (although I doubt it is true) that,
of these women, every one would be willing to use the partial birth
abortion procedure if so advised by her doctor. Indisputably, there
is no "large fraction" of these women who would face a substantial
obstacle to obtaining a safe abortion because of their inability to
use this particular procedure. In fact, it is not clear that any woman would be deprived of a safe abortion by her
inability to obtain a partial birth abortion. More medically
sophisticated minds than ours have searched and failed to identify
a single circumstance (let alone a large fraction) in which partial
birth abortion is required. But no matter. The "ad hoc
nullification" machine is back at full throttle. See Thornburgh v. American College of Obstetricians and
Gynecologists, 476 U. S., at 814 (O'CONNOR, J., dissenting); Madsen v. Women's Health Center, Inc., 512 U. S. 753 , 785 (1994)
(SCALIA, J., concurring in judgment in part and dissenting in
part).

															***

															We were reassured repeatedly in Casey that not all
regulations of abortion are unwarranted and that the States may
express profound respect for fetal life. Under Casey, the
regulation before us today should easily pass constitutional
muster. But the Court's abortion jurisprudence is a particularly
virulent strain of constitutional exegesis. And so today we are
told that 30 States are prohibited from banning one rarely used
form of abortion that they believe to border on infanticide. It is
clear that the Constitution does not compel this result.

															I respectfully dissent.