NOTICE: This opinion is subject to
formal revision before publication in the preliminary print of the
United States Reports. Readers are requested to notify the Reporter
of Decisions, Supreme Court of the United States, Washington,
D. C. 20543, of any typographical or other formal errors, in
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															SUPREME COURT OF THE UNITED STATES

															_________________

															Nos. 20–1530, 20–1531, 20–1778 and
20–1780

															_________________

															WEST VIRGINIA, et al.,
PETITIONERS

															20–1530 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															THE NORTH AMERICAN COAL CORPORATION,
PETITIONER

															20–1531 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															WESTMORELAND MINING HOLDINGS LLC,
PETITIONER

															20–1778 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															NORTH DAKOTA, PETITIONER

															20–1780 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															on writs of certiorari to the united states
court of appeals for the district of columbia circuit

															[June 30, 2022]

															Chief Justice Roberts delivered the opinion of
the Court.

															The Clean Air Act authorizes the Environmental
Protection Agency to regulate power plants by setting a “standard
of performance” for their emission of certain pollutants into the
air. 84Stat. 1683, 42 U. S. C. §7411(a)(1). That standard
may be different for new and existing plants, but in each case it
must reflect the “best system of emission reduction” that the
Agency has determined to be “adequately demonstrated” for the
particular category. §§7411(a)(1), (b)(1), (d). For existing
plants, the States then implement that requirement by issuing rules
restricting emissions from sources within their borders.

															Since passage of the Act 50 years ago, EPA has
exercised this authority by setting performance standards based on
measures that would reduce pollution by causing plants to operate
more cleanly. In 2015, however, EPA issued a new rule concluding
that the “best system of emission reduction” for existing
coal-fired power plants included a requirement that such facilities
reduce their own production of electricity, or subsidize increased
generation by natural gas, wind, or solar sources.

															The question before us is whether this broader
conception of EPA’s authority is within the power granted to it by
the Clean Air Act.

															I

															A

															The Clean Air Act establishes three main
regulatory programs to control air pollution from stationary
sources such as power plants. Clean Air Amendments of 1970, 84Stat.
1676, 42 U. S. C. §7401 et seq. One program
is the New Source Performance Standards program of Section 111, at
issue here. The other two are the National Ambient Air Quality
Standards (NAAQS) program, set out in Sections 108 through 110 of
the Act, 42 U. S. C. §§7408–7410, and the Hazardous Air
Pollutants (HAP) program, set out in Section 112, §7412. To
understand the place and function of Section 111 in the statutory
scheme, some background on the other two programs is in order.

															The NAAQS program addresses air pollutants that
“may reasonably be anticipated to endanger public health or
welfare,” and “the presence of which in the ambient air results
from numerous or diverse mobile or stationary sources.”
§7408(a)(1). After identifying such pollutants, EPA establishes a
NAAQS for each. The NAAQS represents “the maximum airborne
concentration of [the] pollutant that the public health can
tolerate.” Whitman v. American Trucking Assns. , Inc. , 531 U.S.
457 , 465 (2001); see §7409(b). EPA, though, does not choose
which sources must reduce their pollution and by how much to meet
the ambient pollution target. Instead, Section 110 of the Act
leaves that task in the first instance to the States, requiring
each “to submit to [EPA] a plan designed to implement and maintain
such standards within its boundaries.” Train v. Natural
Resources Defense Council , Inc. , 421 U.S.
60 , 65 (1975); §7410.

															The second major program governing stationary
sources is the HAP program. The HAP program primarily targets
pollutants, other than those already covered by a NAAQS, that
present “a threat of adverse human health effects,” including
substances known or anticipated to be “carcinogenic, mutagenic,
teratogenic, neurotoxic,” or otherwise “acutely or chronically
toxic.” §7412(b)(2).

															EPA’s regulatory role with respect to these
toxic pollutants is different in kind from its role in
administering the NAAQS program. There, EPA is generally limited to
determining the maximum safe amount of covered pollutants in the
air. As to each hazardous pollutant, by contrast, the Agency must
promulgate emissions standards for both new and existing major
sources. §7412(d)(1). Those standards must “require the maximum
degree of reduction in emissions . . . that the [EPA]
Administrator, taking into consideration the cost of achieving such
emission reduction, and any non-air quality health and
environmental impacts and energy requirements, determines is
achievable . . . through application of measures,
processes, methods, systems or techniques” of emission reduction.
§7412(d)(2). In other words, EPA must directly require all covered
sources to reduce their emissions to a certain level. And it
chooses that level by determining the “maximum degree of reduction”
it considers “achievable” in practice by using the best existing
technologies and methods. §7412(d)(3).

															Thus, in the parlance of environmental law,
Section 112 directs the Agency to impose “ technology-based standard[s] for hazardous emissions,” Alaska Dept. of
Environmental Conservation v. EPA , 540 U.S. 461, 485,
n. 12 (2004) (emphasis added). This sort of
“ ‘technology-based’ approach focuses upon the control
technologies that are available to industrial entities and requires
the agency to . . . ensur[e] that regulated firms adopt
the appropriate cleanup technology.” T. McGarity, Media-Quality,
Technology, and Cost-Benefit Balancing Strategies for Health and
Environmental Regulation, 46 Law & Contemp. Prob. 159, 160
(Summer 1983) (McGarity). (Such “technologies” are not limited to
literal technology, such as scrubbers; “changes in the design and
operation” of the facility, or “in the way that employees perform
their tasks,” are also available options. Id. , at 163,
n. 18.)

															The third air pollution control scheme is the
New Source Performance Standards program of Section 111. §7411.
That section directs EPA to list “categories of stationary sources”
that it determines “cause[ ], or contribute[ ]
significantly to, air pollution which may reasonably be anticipated
to endanger public health or welfare.” §7411(b)(1)(A). Under
Section 111(b), the Agency must then promulgate for each category
“Federal standards of performance for new sources,” §7411(b)(1)(B).
A “standard of performance” is one that

															“reflects the degree of emission
limitation achievable through the application of the best system of
emission reduction which (taking into account the cost of achieving
such reduction and any nonair quality health and environmental
impact and energy requirements) the [EPA] Administrator determines
has been adequately demonstrated.” §7411(a)(1).

															Thus, the statute directs EPA to (1)
“determine[ ],” taking into account various factors, the “best
system of emission reduction which . . . has been
adequately demonstrated,” (2) ascertain the “degree of
emission limitation achievable through the application” of that
system, and (3) impose an emissions limit on new stationary sources
that “reflects” that amount. Ibid. ; see also 80 Fed. Reg.
64538 (2015). Generally speaking, a source may achieve that
emissions cap any way it chooses; the key is that its pollution be
no more than the amount “achievable through the application of the
best system of emission reduction . . . adequately
demonstrated,” or the BSER. §7411(a)(1); see §7411(b)(5). EPA
undertakes this analysis on a pollutant-by-pollutant basis,
establishing different standards of performance with respect to
different pollutants emitted from the same source category. See, e.g. , 73 Fed. Reg. 35838 (2008); 42 Fed. Reg. 22510
(1977).

															Although the thrust of Section 111 focuses on
emissions limits for new and modified sources—as its
title indicates—the statute also authorizes regulation of certain
pollutants from existing sources. Under Section 111(d), once
EPA “has set new source standards addressing emissions of a
particular pollutant under . . . section 111(b),” 80 Fed.
Reg. 64711, it must then address emissions of that same pollutant
by existing sources—but only if they are not already regulated
under the NAAQS or HAP programs. §7411(d)(1). Existing power
plants, for example, emit many pollutants covered by a NAAQS or HAP
standard. Section 111(d) thus “operates as a gap-filler,”
empowering EPA to regulate harmful emissions not already controlled
under the Agency’s other authorities. American Lung Assn. v. EPA , 985 F.3d 914, 932 (CADC 2021).

															Although the States set the actual rules
governing existing power plants, EPA itself still retains the
primary regulatory role in Section 111(d). The Agency, not the
States, decides the amount of pollution reduction that must
ultimately be achieved. It does so by again determining, as when
setting the new source rules, “the best system of emission
reduction . . . that has been adequately demonstrated for
[existing covered] facilities.” 40 CFR §60.22(b)(5) (2021); see
also 80 Fed. Reg. 64664, and n. 1. The States then submit
plans containing the emissions restrictions that they intend to
adopt and enforce in order not to exceed the permissible level of
pollution established by EPA. See §§60.23, 60.24; 42
U. S. C. §7411(d)(1).

															Reflecting the ancillary nature of Section
111(d), EPA has used it only a handful of times since the enactment
of the statute in 1970. See 80 Fed. Reg. 64703, and n. 275
(past regulations pertained to “four pollutants from five source
categories”). For instance, the Agency has established emissions
limits on acid mist from sulfuric acid production, 41 Fed. Reg.
48706 (1976) (identifying “fiber mist eliminator” technology as
BSER); sulfide gases released by kraft pulp mills, 44 Fed. Reg.
29829 (1979) (determining BSER to be a combination of scrubbers,
incineration, filtration systems, and temperature control); and
emissions of various harmful gases from municipal landfills, 61
Fed. Reg. 9907 (1996) (setting BSER as use of a flare to combust
the gases). It was thus only a slight overstatement for one of the
architects of the 1990 amendments to the Clean Air Act to refer to
Section 111(d) as an “obscure, never-used section of the law.”
Hearings on S. 300 et al. before the Subcommittee on
Environmental Protection of the Senate Committee on Environment and
Public Works, 100th Cong., 1st Sess., 13 (1987) (remarks of Sen.
Durenberger).

															B

															Things changed in October 2015, when EPA
promulgated two rules addressing carbon dioxide pollution from
power plants—one for new plants under Section 111(b), the other for
existing plants under Section 111(d). Both were premised on the
Agency’s earlier finding that carbon dioxide is an “air pollutant”
that “may reasonably be anticipated to endanger public health or
welfare” by causing climate change. 80 Fed. Reg. 64530. Carbon
dioxide is not subject to a NAAQS and has not been listed as a
toxic pollutant.

															The first rule announced by EPA established
federal carbon emissions limits for new power plants of two
varieties: fossil-fuel-fired electric steam generating units
(mostly coal fired) and natural-gas-fired stationary combustion
turbines. Id. , at 64512. Following the statutory process set
out above, the Agency determined the BSER for the two categories of
sources. For steam generating units, for instance, EPA determined
that the BSER was a combination of high-efficiency production
processes and carbon capture technology. See 80 Fed. Reg. 64512.
EPA then set the emissions limit based on the amount of carbon
dioxide that a plant would emit with these technologies in place. Id. , at 64513.

															The second rule was triggered by the first:
Because EPA was now regulating carbon dioxide from new coal
and gas plants, Section 111(d) required EPA to also address carbon
emissions from existing coal and gas plants. See
§7411(d)(1). It did so through what it called the Clean Power Plan
rule.

															In that rule, EPA established “final emission
guidelines for states to follow in developing plans” to regulate
existing power plants within their borders. Id. , at 64662.
To arrive at the guideline limits, EPA did the same thing it does
when imposing federal regulations on new sources: It identified the
BSER.

															The BSER that the Agency selected for existing
coal-fired power plants, however, was quite different from the BSER
it had chosen for new sources. The BSER for existing plants
included three types of measures, which the Agency called “building
blocks.” Id. , at 64667. The first building block was “heat
rate improvements” at coal-fired plants—essentially practices such
plants could undertake to burn coal more efficiently. Id. ,
at 64727 . But such improvements, EPA stated, would “lead to
only small emission reductions,” because coal-fired power plants
were already operating near optimum efficiency. Ibid. On the
Agency’s view, “much larger emission reductions [were] needed from
[coal-fired plants] to address climate change.” Ibid. So the Agency included two additional building
blocks in its BSER, both of which involve what it called
“generation shifting from higher-emitting to lower-emitting”
producers of electricity. Id. , at 64728. Building block two
was a shift in electricity production from existing coal-fired
power plants to natural-gas-fired plants. Ibid. Because
natural gas plants produce “typically less than half as much”
carbon dioxide per unit of electricity created as coal-fired
plants, the Agency explained, “this generation shift [would]
reduce[] CO2 emissions.” Ibid. Building block three worked
the same way, except that the shift was from both coal- and
gas-fired plants to “new low- or zero-carbon generating capacity,”
mainly wind and solar. Id. , at 64729, 64748. “Most of the
CO2 controls” in the rule came from the application of building
blocks two and three. Id. , at 64728.

															The Agency identified three ways in which a
regulated plant operator could implement a shift in generation to
cleaner sources. Id. , at 64731. First, an operator could
simply reduce the regulated plant’s own production of electricity.
Second, it could build a new natural gas plant, wind farm, or solar
installation, or invest in someone else’s existing facility and
then increase generation there. Ibid. Finally, operators
could purchase emission allowances or credits as part of a
cap-and-trade regime. Id. , at 64731–64732. Under such a
scheme, sources that achieve a reduction in their emissions can
sell a credit representing the value of that reduction to others,
who are able to count it toward their own applicable emissions
caps.

															EPA explained that taking any of these steps
would implement a sector-wide shift in electricity production from
coal to natural gas and renewables. Id. , at 64731. Given the
integrated nature of the power grid, “adding electricity to the
grid from one generator will result in the instantaneous reduction
in generation from other generators,” and “reductions in generation
from one generator lead to the instantaneous increase in
generation” by others. Id. , at 64769. So coal plants,
whether by reducing their own production, subsidizing an increase
in production by cleaner sources, or both, would cause a shift
toward wind, solar, and natural gas.

															Having decided that the “best system of emission
reduction . . . adequately demonstrated” was one that
would reduce carbon pollution mostly by moving production to
cleaner sources, EPA then set about determining “the degree of
emission limitation achievable through the application” of that
system. 42 U. S. C. §7411(a)(1). The Agency recognized
that—given the nature of generation shifting—it could choose from
“a wide range of potential stringencies for the BSER.” 80 Fed. Reg.
64730. Put differently, in translating the BSER into an operational
emissions limit, EPA could choose whether to require anything from
a little generation shifting to a great deal. The Agency settled on
what it regarded as a “reasonable” amount of shift, which it based
on modeling of how much more electricity both natural gas and
renewable sources could supply without causing undue cost increases
or reducing the overall power supply. Id. , at 64797–64811.
Based on these changes, EPA projected that by 2030, it would be
feasible to have coal provide 27% of national electricity
generation, down from 38% in 2014. Id. , at 64665, 64694; see
Dept. of Energy, U. S. Energy Information Admin., Monthly
Energy Review (May 2015), Electricity Net Generation: Electric
Power Sector, p. 106 (Table 7.2b).

															From these significant projected reductions in
generation, EPA developed a series of complex equations to
“determine the emission performance rates” that States would be
required to implement. 80 Fed. Reg. 64815. The calculations
resulted in numerical emissions ceilings so strict that no existing
coal plant would have been able to achieve them without engaging in
one of the three means of shifting generation described above.
Indeed, the emissions limit the Clean Power Plan established for
existing power plants was actually stricter than the cap
imposed by the simultaneously published standards for new plants. Compare id. , at 64742, with id. , at
64513.

															The point, after all, was to compel the transfer
of power generating capacity from existing sources to wind and
solar. The White House stated that the Clean Power Plan would
“drive a[n] . . . aggressive transformation in the
domestic energy industry.” White House Fact Sheet, App. in American Lung Assn . v. EPA , No. 19–1140 etc. (CADC),
p. 2076. EPA’s own modeling concluded that the rule would
entail billions of dollars in compliance costs (to be paid in the
form of higher energy prices), require the retirement of dozens of
coal-fired plants, and eliminate tens of thousands of jobs across
various sectors. EPA, Regulatory Impact Analysis for the Clean
Power Plan Final Rule 3–22, 3–30, 3–33, 6–24, 6–25 (2015). The
Energy Information Administration reached similar conclusions,
projecting that the rule would cause retail electricity prices to
remain persistently 10% higher in many States, and would reduce GDP
by at least a trillion 2009 dollars by 2040. Dept. of Energy,
Analysis of the Impacts of the Clean Power Plan 21, 63–64 (May
2015).

															C

															These projections were never tested, because
the Clean Power Plan never went into effect. The same day that EPA
promulgated the rule, dozens of parties (including 27 States)
petitioned for review in the D. C. Circuit. After that court
declined to enter a stay of the rule, the challengers sought the
same relief from this Court. We granted a stay, preventing the rule
from taking effect. West Virginia v. EPA , 577 U.S.
1126 (2016). The Court of Appeals later heard argument on the
merits en banc. But before it could issue a decision, there was a
change in Presidential administrations. The new administration
requested that the litigation be held in abeyance so that EPA could
reconsider the Clean Power Plan. The D. C. Circuit obliged,
and later dismissed the petitions for review as moot.

															EPA eventually repealed the rule in 2019,
concluding that the Clean Power Plan had been “in excess of its
statutory authority” under Section 111(d). 84 Fed. Reg. 32523
(2019). Specifically, the Agency concluded that generation shifting
should not have been considered as part of the BSER. The Agency
interpreted Section 111 as “limit[ing] the BSER to those systems
that can be put into operation at a building, structure,
facility, or installation,” such as “add-on controls” and
“inherently lower-emitting processes/practices/designs.” Id. , at 32524. It then explained that the Clean Power Plan,
rather than setting the standard “based on the application of
equipment and practices at the level of an individual facility,”
had instead based it on “a shift in the energy generation mix at
the grid level,” id. , at 32523—not the sort of measure that
has “a potential for application to an individual source.” Id. , at 32524.

															The Agency determined that “the interpretative
question raised” by the Clean Power Plan—“ i.e. , whether a
‘system of emission reduction’ can consist of generation-shifting
measures”—fell under the “major question doctrine.” Id. , at
32529. Under that doctrine, EPA explained, courts “expect Congress
to speak clearly if it wishes to assign to an agency decisions of
vast economic and political significance.” Ibid. (quoting Utility Air Regulatory Group v. EPA , 573 U.S.
302 , 324 (2014) (internal quotation marks omitted)). The Agency
concluded that the Clean Power Plan was such a decision, for a
number of reasons. Its “generation-shifting scheme was projected to
have billions of dollars of impact.” 84 Fed. Reg. 32529. “[N]o
section 111 rule of the scores issued ha[d] ever been based on
generation shifting.” Ibid. And that novel reading of the
statute would empower EPA “to order the wholesale restructuring of
any industrial sector” based only on its discretionary assessment
of “such factors as ‘cost’ and ‘feasibility.’ ” Ibid. EPA argued that under the major questions
doctrine, a clear statement was necessary to conclude that Congress
intended to delegate authority “of this breadth to regulate a
fundamental sector of the economy.” Ibid. It found none.
“Indeed,” it concluded, given the text and structure of the
statute, “Congress has directly spoken to this precise question and
precluded” the use of measures such as generation shifting. Ibid. In the same rulemaking, the Agency replaced the
Clean Power Plan by promulgating a different Section 111(d)
regulation, known as the Affordable Clean Energy (ACE) Rule. Id. , at 32532. Based on its view of what measures may
permissibly make up the BSER, EPA determined that the best system
would be akin to building block one of the Clean Power Plan: a
combination of equipment upgrades and operating practices that
would improve facilities’ heat rates. Id. , at 32522, 32537.
The ACE Rule determined that the application of its BSER measures
would result in only small reductions in carbon dioxide emissions. Id. , at 32561.

															D

															A number of States and private parties
immediately filed petitions for review in the D. C. Circuit,
challenging EPA’s repeal of the Clean Power Plan and its enactment
of the replacement ACE Rule. Other States and private
entities—including petitioners here West Virginia, North Dakota,
Westmoreland Mining Holdings LLC, and The North American Coal
Corporation (NACC)—intervened to defend both actions.

															The Court of Appeals consolidated all 12
petitions for review into one case. It then held that EPA’s “repeal
of the Clean Power Plan rested critically on a mistaken reading of
the Clean Air Act”—namely, that generation shifting cannot be a
“system of emission reduction” under Section 111. 985 F. 3d,
at 995. To the contrary, the court concluded, the statute could
reasonably be read to encompass generation shifting. As part of
that analysis, the Court of Appeals concluded that the major
questions doctrine did not apply, and thus rejected the need for a
clear statement of congressional intent to delegate such power to
EPA. Id. , at 959–968. Having found that EPA misunderstood
the scope of its authority under the Clean Air Act, the Court
vacated the Agency’s repeal of the Clean Power Plan and remanded to
the Agency for further consideration. Id. , at 995 . It
also vacated and remanded the replacement rule, the ACE Rule, for
the same reason. Ibid. The court’s decision, handed down on January 19,
2021, was quickly followed by another change in Presidential
administrations. One month later, EPA moved the Court of Appeals to
partially stay the issuance of its mandate as it pertained to the
Clean Power Plan. The Agency did so to ensure that the Clean Power
Plan would not immediately go back into effect. Respondents’ Motion
for a Partial Stay of Issuance of the Mandate in American Lung
Assn . v. EPA , No. 19–1140 etc. (CADC), p. 4. EPA
believed that such a result would not make sense while it was in
the process of considering whether to promulgate a new Section
111(d) rule. Ibid . No party opposed the motion, and the
court accordingly stayed its vacatur of the Agency’s repeal of the
Clean Power Plan.

															Westmoreland, NACC, and the States defending the
repeal of the Clean Power Plan all filed petitions for certiorari.
We granted the petitions and consolidated the cases. 595 U. S.
___ (2021).

															II

															We first consider the Government’s contention
that no petitioner has Article III standing to seek our review.

															Although most disputes over standing concern
whether a plaintiff has satisfied the requirement when filing suit,
“Article III demands that an actual controversy persist throughout
all stages of litigation.” Hollingsworth v. Perry , 570 U.S.
693 , 705 (2013) (internal quotation marks omitted). The
requirement of standing “must be met by persons seeking appellate
review, just as it must be met by persons appearing in courts of
first instance.” Arizonans for Official English v. Arizona , 520 U.S.
43 , 64 (1997). In considering a litigant’s standing to appeal,
the question is whether it has experienced an injury “fairly
traceable to the judgment below. ” Food Marketing
Institute v. Argus Leader Media , 588 U. S. ___, ___
(2019) (slip op., at 4) (emphasis added; internal quotation marks
omitted). If so, and a “favorable ruling” from the appellate court
“would redress [that] injury,” then the appellant has a cognizable
Article III stake. Ibid. Here, it is apparent that at least one group of
petitioners—the state petitioners—are injured by the Court of
Appeals’ judgment. That judgment vacated “the ACE rule and its embedded repeal of the Clean Power Plan,” 985 F. 3d, at
995 (emphasis added), and accordingly purports to bring the Clean
Power Plan back into legal effect. Thus, to the extent the Clean
Power Plan harms the States, the D. C. Circuit’s judgment
inflicts the same injury. And there can be “little question” that
the rule does injure the States, since they are “the object
of ” its requirement that they more stringently regulate power
plant emissions within their borders. Lujan v. Defenders
of Wildlife , 504 U.S.
555 , 561–562 (1992).

															The Government counters that “agency and
judicial actions” subsequent to the court’s entry of judgment have
“eliminated any . . . possibility” of injury. Brief for
Federal Respondents 16. First, after the decision, EPA informed the
Court of Appeals that it does not intend to enforce the Clean Power
Plan because it has decided to promulgate a new Section 111(d)
rule. Second, on EPA’s request, the lower court stayed the part of
its judgment that vacated the repeal, pending that new rulemaking.
“These circumstances,” says the Government, “have mooted the
prior dispute as to the CPP Repeal Rule’s legality.” Id. , at
17 (emphasis added).

															That Freudian slip, however, reveals the basic
flaw in the Government’s argument: It is the doctrine of mootness , not standing, that addresses whether “an
intervening circumstance [has] deprive[d] the plaintiff of a
personal stake in the outcome of the lawsuit.” Genesis
HealthCare Corp. v. Symczyk , 569 U.S.
66 , 72 (2013) (internal quotation marks omitted); see also Friends of the Earth , Inc. v. Laidlaw
Environmental Services (TOC) , Inc. , 528 U.S.
167 , 189–192 (2000). The distinction matters because the
Government, not petitioners, bears the burden to establish that a
once-live case has become moot. Id. , at 189; Adarand
Constructors , Inc. v. Slater , 528 U.S.
216 , 222 (2000) ( per curiam ).

															That burden is “heavy” where, as here, “[t]he
only conceivable basis for a finding of mootness in th[e] case is
[the respondent’s] voluntary conduct.” Friends of the Earth ,
528 U. S., at 189. Although the Government briefly argues that
the lower court’s stay of its mandate extinguished the controversy,
it cites no authority for that proposition, and it does not make
sense: Lower courts frequently stay their mandates when notified
that the losing party intends to seek our certiorari review. So the
Government’s mootness argument boils down to its representation
that EPA has no intention of enforcing the Clean Power Plan prior
to promulgating a new Section 111(d) rule.

															But “voluntary cessation does not moot a case”
unless it is “absolutely clear that the allegedly wrongful behavior
could not reasonably be expected to recur.” Parents Involved in
Community Schools v. Seattle School Dist. No. 1 , 551 U.S.
701 , 719 (2007). Here the Government “nowhere suggests that if
this litigation is resolved in its favor it will not” reimpose
emissions limits predicated on generation shifting; indeed, it
“vigorously defends” the legality of such an approach. Ibid. We do not dismiss a case as moot in such circumstances. See City
of Mesquite v. Aladdin’s Castle , Inc. , 455 U.S.
283 , 288–289 (1982). The case thus remains justiciable, and we
may turn to the merits.

															III

															A

															In devising emissions limits for power plants,
EPA first “determines” the “best system of emission reduction”
that—taking into account cost, health, and other factors—it finds
“has been adequately demonstrated.” 42 U. S. C.
§7411(a)(1). The Agency then quantifies “the degree of emission
limitation achievable” if that best system were applied to the
covered source. Ibid. ; see also 80 Fed. Reg. 64719. The
BSER, therefore, “is the central determination that the EPA must
make in formulating [its emission] guidelines” under Section 111. Id. , at 64723. The issue here is whether restructuring the
Nation’s overall mix of electricity generation, to transition from
38% coal to 27% coal by 2030, can be the “best system of emission
reduction” within the meaning of Section 111.

															“It is a fundamental canon of statutory
construction that the words of a statute must be read in their
context and with a view to their place in the overall statutory
scheme.” Davis v. Michigan Dept. of Treasury , 489 U.S.
803 , 809 (1989). Where the statute at issue is one that confers
authority upon an administrative agency, that inquiry must be
“shaped, at least in some measure, by the nature of the question
presented”—whether Congress in fact meant to confer the power the
agency has asserted. FDA v. Brown & Williamson
Tobacco Corp. , 529 U.S.
120 , 159 (2000) . In the ordinary case, that context has
no great effect on the appropriate analysis. Nonetheless, our
precedent teaches that there are “extraordinary cases” that call
for a different approach—cases in which the “history and the
breadth of the authority that [the agency] has asserted,” and the
“economic and political significance” of that assertion, provide a
“reason to hesitate before concluding that Congress” meant to
confer such authority. Id. , at 159–160.

															Such cases have arisen from all corners of the
administrative state. In Brown & Williamson , for
instance, the Food and Drug Administration claimed that its
authority over “drugs” and “devices” included the power to
regulate, and even ban, tobacco products. Id. , at 126–127.
We rejected that “expansive construction of the statute,”
concluding that “Congress could not have intended to delegate” such
a sweeping and consequential authority “in so cryptic a fashion.” Id. , at 160. In Alabama Assn. of Realtors v. Department of Health and Human Servs. , 594 U. S. ___,
___ (2021) ( per curiam ) (slip op., at 3), we concluded
that the Centers for Disease Control and Prevention could not,
under its authority to adopt measures “necessary to prevent the
. . . spread of ” disease, institute a nationwide
eviction moratorium in response to the COVID–19 pandemic. We found
the statute’s language a “wafer-thin reed” on which to rest such a
measure, given “the sheer scope of the CDC’s claimed authority,”
its “unprecedented” nature, and the fact that Congress had failed
to extend the moratorium after previously having done so. Id. , at ___–___ (slip op., at 6–8).

															Our decision in Utility Air addressed
another question regarding EPA’s authority—namely, whether EPA
could construe the term “air pollutant,” in a specific provision of
the Clean Air Act, to cover greenhouse gases. 573 U. S., at
310. Despite its textual plausibility, we noted that the Agency’s
interpretation would have given it permitting authority over
millions of small sources, such as hotels and office buildings,
that had never before been subject to such requirements. Id. , at 310, 324. We declined to uphold EPA’s claim of
“unheralded” regulatory power over “a significant portion of the
American economy.” Id. , at 324. In Gonzales v. Oregon , 546 U.S.
243 (2006), we confronted the Attorney General’s assertion that
he could rescind the license of any physician who prescribed a
controlled substance for assisted suicide, even in a State where
such action was legal. The Attorney General argued that this came
within his statutory power to revoke licenses where he found them
“inconsistent with the public interest,” 21 U. S. C.
§823(f ). We considered the “idea that Congress gave [him]
such broad and unusual authority through an implicit delegation
. . . not sustainable.” 546 U. S., at 267. Similar
considerations informed our recent decision invalidating the
Occupational Safety and Health Administration’s mandate that “84
million Americans . . . either obtain a COVID–19 vaccine
or undergo weekly medical testing at their own expense.” National Federation of Independent Business v. Occupational Safety and Health Administration , 595
U. S. ___, ___ (2022) ( per curiam ) (slip op., at
5). We found it “telling that OSHA, in its half century of
existence,” had never relied on its authority to regulate
occupational hazards to impose such a remarkable measure. Id. , at ___ (slip op., at 8).

															All of these regulatory assertions had a
colorable textual basis. And yet, in each case, given the various
circumstances, “common sense as to the manner in which Congress
[would have been] likely to delegate” such power to the agency at
issue, Brown & Williamson , 529 U. S., at 133, made
it very unlikely that Congress had actually done so. Extraordinary
grants of regulatory authority are rarely accomplished through
“modest words,” “vague terms,” or “subtle device[s].” Whitman , 531 U. S., at 468. Nor does Congress typically
use oblique or elliptical language to empower an agency to make a
“radical or fundamental change” to a statutory scheme. MCI
Telecommunications Corp. v. American Telephone &
Telegraph Co. , 512 U.S.
218 , 229 (1994). Agencies have only those powers given to them
by Congress, and “enabling legislation” is generally not an “open
book to which the agency [may] add pages and change the plot line.”
E. Gellhorn & P. Verkuil, Controlling Chevron - Based
Delegations, 20 Cardozo L. Rev. 989, 1011 (1999). We presume
that “Congress intends to make major policy decisions itself, not
leave those decisions to agencies.” United States Telecom
Assn. v. FCC , 855 F.3d 381, 419 (CADC 2017) (Kavanaugh,
J., dissenting from denial of rehearing en banc).

															Thus, in certain extraordinary cases, both
separation of powers principles and a practical understanding of
legislative intent make us “reluctant to read into ambiguous
statutory text” the delegation claimed to be lurking there. Utility Air , 573 U. S., at 324. To convince us
otherwise, something more than a merely plausible textual basis for
the agency action is necessary. The agency instead must point to
“clear congressional authorization” for the power it claims. Ibid. The dissent criticizes us for “announc[ing] the
arrival” of this major questions doctrine, and argues that each of
the decisions just cited simply followed our “ordinary method” of
“normal statutory interpretation,” post, at 13, 15 (opinion
of Kagan, J.). But in what the dissent calls the “key case” in this
area, Brown & Williamson , post, at 15, the Court
could not have been clearer: “In extraordinary cases . . . there
may be reason to hesitate” before accepting a reading of a statute
that would, under more “ordinary” circumstances, be upheld. 529
U. S., at 159. Or, as we put it more recently, we “typically
greet” assertions of “extravagant statutory power over the national
economy” with “skepticism.” Utility Air , 573 U. S., at
324. The dissent attempts to fit the analysis in these cases within
routine statutory interpretation, but the bottom line—a requirement
of “clear congressional authorization,” ibid. —confirms that
the approach under the major questions doctrine is distinct.

															As for the major questions doctrine
“label[ ],” post, at 13, it took hold because it refers
to an identifiable body of law that has developed over a series of
significant cases all addressing a particular and recurring
problem: agencies asserting highly consequential power beyond what
Congress could reasonably be understood to have granted. Scholars
and jurists have recognized the common threads between those
decisions. So have we. See Utility Air , 573 U. S., at
324 (citing Brown & Williamson and MCI ); King v. Burwell , 576 U.S. 473, 486 (2015) (citing Utility Air , Brown & Williamson , and Gonzales ).

															B

															Under our precedents, this is a major
questions case. In arguing that Section 111(d) empowers it to
substantially restructure the American energy market, EPA
“claim[ed] to discover in a long-extant statute an unheralded
power” representing a “transformative expansion in [its] regulatory
authority.” Utility Air , 573 U. S., at 324. It located
that newfound power in the vague language of an “ancillary
provision[ ]” of the Act, Whitman , 531 U. S., at
468, one that was designed to function as a gap filler and had
rarely been used in the preceding decades. And the Agency’s
discovery allowed it to adopt a regulatory program that Congress
had conspicuously and repeatedly declined to enact itself. Brown
& Williamson , 529 U. S., at 159–160; Gonzales ,
546 U. S., at 267–268; Alabama Assn. , 594 U. S.,
at ___, ___ (slip op., at 2, 8). Given these circumstances, there
is every reason to “hesitate before concluding that Congress” meant
to confer on EPA the authority it claims under Section 111(d). Brown & Williamson , 529 U. S., at 159–160.

															Prior to 2015, EPA had always set emissions
limits under Section 111 based on the application of measures that
would reduce pollution by causing the regulated source to operate
more cleanly. See, e.g. , 41 Fed. Reg. 48706 (requiring
“degree of control achievable through the application of fiber mist
eliminators”); see also supra , at 6. It had never devised a
cap by looking to a “system” that would reduce pollution simply by
“shifting” polluting activity “from dirtier to cleaner sources.” 80
Fed. Reg. 64726; see id. , at 64738 (“[O]ur traditional
interpretation . . . has allowed regulated entities to
produce as much of a particular good as they desire provided that
they do so through an appropriately clean (or low-emitting)
process.”). And as Justice Frankfurter has noted, “just as
established practice may shed light on the extent of power conveyed
by general statutory language, so the want of assertion of power by
those who presumably would be alert to exercise it, is equally
significant in determining whether such power was actually
conferred.” FTC v. Bunte Brothers , Inc. , 312 U.S.
349 , 352 (1941).

															The Government quibbles with this description of
the history of Section 111(d), pointing to one rule that it says
relied upon a cap-and-trade mechanism to reduce emissions. See 70
Fed. Reg. 28616 (2005) (Mercury Rule). The legality of that choice
was controversial at the time and was never addressed by a court.
See New Jersey v. EPA , 517 F.3d 574 (CADC 2008)
(vacating on other grounds). Even assuming the Rule was valid,
though, it still does not help the Government. In that regulation,
EPA set the actual “emission cap”— i.e. , the limit on
emissions that sources would be required to meet—“based on the
level of [mercury] emissions reductions that w[ould] be achievable
by” the use of “technologies [that could be] installed and
operational on a nationwide basis” in the relevant
timeframe—namely, wet scrubbers. 70 Fed. Reg. 28620–28621. In other
words, EPA set the cap based on the application of particular
controls, and regulated sources could have complied by installing
them. By contrast, and by design, there is no control a coal plant
operator can deploy to attain the emissions limits established by
the Clean Power Plan. See supra , at 10. The Mercury Rule,
therefore, is no precedent for the Clean Power Plan. To the
contrary, it was one more entry in an unbroken list of prior
Section 111 rules that devised the enforceable emissions limit by
determining the best control mechanisms available for the
source.[ 1 ]

															This consistent understanding of “system[s] of
emission reduction” tracked the seemingly universal view, as stated
by EPA in its inaugural Section 111(d) rulemaking, that “Congress
intended a technology-based approach” to regulation in that
Section. 40 Fed. Reg. 53343 (1975); see id. , at 53341
(“degree of control to be reflected in EPA’s emission guidelines”
will be based on “application of best adequately demonstrated
control technology”).[ 2 ] A
technology-based standard, recall, is one that focuses on improving
the emissions performance of individual sources. EPA “commonly
referred to” the “level of control” required as a “best
demonstrated technology (BDT)” standard, 73 Fed. Reg. 34073, and
consistently applied it as such. E.g. , 61 Fed. Reg. 9907
(declaring “BDT” to be “a well-designed and well-operated gas
collection system and . . . a control device capable of
reducing [harmful gases] in the collected gas by 98
weight-percent.”).

															Indeed, EPA nodded to this history in the Clean
Power Plan itself, describing the sort of “systems of emission
reduction” it had always before selected—“efficiency improvements,
fuel-switching,” and “add-on controls”—as “more traditional air
pollution control measures.” 80 Fed. Reg. 64784. The Agency noted
that it had “considered” such measures as potential systems of
emission reduction for carbon dioxide, ibid. , including a
measure it ultimately adopted as a “component” of the BSER, namely,
heat rate improvements. Id. , at 64727.

															But, the Agency explained, in order to
“control[ ] CO2 from affected [plants] at levels
. . . necessary to mitigate the dangers presented by
climate change,” it could not base the emissions limit on “measures
that improve efficiency at the power plants.” Id. , at 64728.
“The quantity of emissions reductions resulting from the
application of these measures” would have been “too small.” Id. , at 64727. Instead, to attain the necessary “critical
CO2 reductions,” EPA adopted what it called a “broader,
forward-thinking approach to the design” of Section 111
regulations. Id. , at 64703. Rather than focus on improving
the performance of individual sources, it would “improve the overall power system by lowering the carbon intensity of
power generation.” Ibid. (emphasis added). And it would do
that by forcing a shift throughout the power grid from one type of
energy source to another. In the words of the then-EPA
Administrator, the rule was “not about pollution control” so much
as it was “an investment opportunity” for States, especially
“investments in renewables and clean energy.” Oversight Hearing on
EPA’s Proposed Carbon Pollution Standards for Existing Power Plants
before the Senate Committee on Environment and Public Works, 113th
Cong., 2d Sess., p. 33 (2014).

															This view of EPA’s authority was not only
unprecedented; it also effected a “fundamental revision of the
statute, changing it from [one sort of] scheme of . . .
regulation” into an entirely different kind. MCI , 512
U. S., at 231. Under the Agency’s prior view of Section 111,
its role was limited to ensuring the efficient pollution
performance of each individual regulated source. Under that
paradigm, if a source was already operating at that level, there
was nothing more for EPA to do. Under its newly “discover[ed]”
authority, Utility Air , 573 U. S., at 324, however, EPA
can demand much greater reductions in emissions based on a very
different kind of policy judgment: that it would be “best” if coal
made up a much smaller share of national electricity generation.
And on this view of EPA’s authority, it could go further, perhaps
forcing coal plants to “shift” away virtually all of their
generation— i.e. , to cease making power altogether.[ 3 ]

															The Government attempts to downplay the
magnitude of this “unprecedented power over American industry.” Industrial Union Dept. , AFL–CIO v. American
Petroleum Institute , 448 U.S.
607 , 645 (1980) (plurality opinion). The amount of generation
shifting ordered, it argues, must be “adequately demonstrated” and
“best” in light of the statutory factors of “cost,” “nonair quality
health and environmental impact,” and “energy requirements.” 42
U. S. C. §7411(a)(1). EPA therefore must limit the
magnitude of generation shift it demands to a level that will not
be “exorbitantly costly” or “threaten the reliability of the grid.”
Brief for Federal Respondents 42.

															But this argument does not so much limit the breadth of the Government’s claimed authority as reveal it. On EPA’s view of Section 111(d), Congress implicitly tasked it,
and it alone, with balancing the many vital considerations of
national policy implicated in deciding how Americans will get their
energy. EPA decides, for instance, how much of a switch from coal
to natural gas is practically feasible by 2020, 2025, and 2030
before the grid collapses, and how high energy prices can go as a
result before they become unreasonably “exorbitant.”

															There is little reason to think Congress
assigned such decisions to the Agency. For one thing, as EPA itself
admitted when requesting special funding, “Understand[ing] and
project[ing] system-wide . . . trends in areas such as
electricity transmission, distribution, and storage” requires
“technical and policy expertise not traditionally needed in
EPA regulatory development.” EPA, Fiscal Year 2016: Justification
of Appropriation Estimates for the Committee on Appropriations 213
(2015) (emphasis added). “When [an] agency has no comparative
expertise” in making certain policy judgments, we have said,
“Congress presumably would not” task it with doing so. Kisor v. Wilkie , 588 U. S. ___, ___ (2019) (slip op., at 17);
see also Gonzales , 546 U. S., at 266–267.

															We also find it “highly unlikely that Congress
would leave” to “agency discretion” the decision of how much coal-
based generation there should be over the coming decades. MCI , 512 U. S., at 231; see also Brown &
Williamson , 529 U. S., at 160 (“We are confident that
Congress could not have intended to delegate a decision of such
economic and political significance to an agency in so cryptic a
fashion.”). The basic and consequential tradeoffs involved in such
a choice are ones that Congress would likely have intended for
itself. See W. Eskridge, Interpreting Law: A Primer on How To Read
Statutes and the Constitution 288 (2016) (“Even if Congress has
delegated an agency general rulemaking or adjudicatory power,
judges presume that Congress does not delegate its authority to
settle or amend major social and economic policy decisions.”).
Congress certainly has not conferred a like authority upon EPA
anywhere else in the Clean Air Act. The last place one would expect
to find it is in the previously little-used backwater of Section
111(d).

															The dissent contends that there is nothing
surprising about EPA dictating the optimal mix of energy sources
nationwide, since that sort of mandate will reduce air pollution
from power plants, which is EPA’s bread and butter. Post , at
20–22. But that does not follow. Forbidding evictions may slow the
spread of disease, but the CDC’s ordering such a measure certainly
“raise[s] an eyebrow.” Post , at 18. We would not expect the
Department of Homeland Security to make trade or foreign policy
even though doing so could decrease illegal immigration. And no one
would consider generation shifting a “tool” in OSHA’s “toolbox,” post , at 21, even though reducing generation at coal plants
would reduce workplace illness and injury from coal dust.

															The dissent also cites our decision in American Elec. Power Co. v. Connecticut , 564 U.S.
410 (2011). Post , at 20. The question there, however,
was whether Congress wanted district court judges to decide, under
unwritten federal nuisance law, “whether and how to regulate
carbon- dioxide emissions from powerplants.” 564 U. S., at
426. We answered no, given the existence of Section 111(d). But we
said nothing about the ways in which Congress intended EPA to
exercise its power under that provision. And it is doubtful we had
in mind that it would claim the authority to require a large shift
from coal to natural gas, wind, and solar. After all, EPA had never
regulated in that manner, despite having issued many prior rules
governing power plants under Section 111. See, e.g. , 71 Fed.
Reg. 9866 (2006); 70 Fed. Reg. 28616; 44 Fed. Reg. 33580; 36 Fed.
Reg. 24875 (1973).[ 4 ]

															Finally, we cannot ignore that the regulatory
writ EPA newly uncovered conveniently enabled it to enact a program
that, long after the dangers posed by greenhouse gas emissions “had
become well known, Congress considered and rejected” multiple
times. Brown & Williamson , 529 U. S., at 144; see
also Alabama Assn. , 594 U. S., at ___ (slip op., at 2); Bunte Brothers , 312 U. S., at 352 (lack of authority
not previously exercised “reinforced by [agency’s] unsuccessful
attempt . . . to secure from Congress an express grant of
[the challenged] authority”). At bottom, the Clean Power Plan
essentially adopted a cap-and-trade scheme, or set of state
cap-and-trade schemes, for carbon. See 80 Fed. Reg. 64734
(“Emissions trading is . . . an integral part of our BSER
analysis.”). Congress, however, has consistently rejected proposals
to amend the Clean Air Act to create such a program. See, e.g. , American Clean Energy and Security Act of 2009,
H. R. 2454, 111th Cong., 1st Sess.; Clean Energy Jobs and
American Power Act, S. 1733, 111th Cong., 1st Sess. (2009). It has
also declined to enact similar measures, such as a carbon tax. See, e.g. , Climate Protection Act of 2013, S. 332, 113th Cong.,
1st Sess.; Save our Climate Act of 2011, H. R. 3242, 112th
Cong., 1st Sess. “The importance of the issue,” along with the fact
that the same basic scheme EPA adopted “has been the subject of an
earnest and profound debate across the country, . . .
makes the oblique form of the claimed delegation all the more
suspect.” Gonzales , 546 U. S., at 267–268 (internal
quotation marks omitted).

															C

															Given these circumstances, our precedent
counsels skepticism toward EPA’s claim that Section 111 empowers it
to devise carbon emissions caps based on a generation shifting
approach. To overcome that skepticism, the Government must—under
the major questions doctrine—point to “clear congressional
authorization” to regulate in that manner. Utility Air , 573
U. S., at 324.

															All the Government can offer, however, is the
Agency’s authority to establish emissions caps at a level
reflecting “the application of the best system of emission
reduction . . . adequately demonstrated.” 42
U. S. C. §7411(a)(1). As a matter of “definitional
possibilities,” FCC v. AT&T Inc. , 562 U.S.
397 , 407 (2011), generation shifting can be described as a
“system”—“an aggregation or assemblage of objects united by some
form of regular interaction,” Brief for Federal Respondents
31—capable of reducing emissions. But of course almost anything
could constitute such a “system”; shorn of all context, the word is
an empty vessel. Such a vague statutory grant is not close to the
sort of clear authorization required by our precedents.

															The Government, echoed by the other respondents,
looks to other provisions of the Clean Air Act for support. It
points out that the Act elsewhere uses the word “system” or
“similar words” to describe cap-and-trade schemes or other
sector-wide mechanisms for reducing pollution. Ibid . The
Acid Rain program set out in Title IV of the Act establishes a
cap-and-trade scheme for reducing sulfur dioxide emissions, which
the statute refers to as an “emission allocation and transfer system .” §7651(b) (emphasis added). And Section 110 of the
NAAQS program specifies that “marketable permits” and “auctions of
emissions rights” qualify as “control measures, means, or
techniques” that States may adopt in their state implementation
plans in order “to meet the applicable requirements of ” a
NAAQS. §7410(a)(2)(A). If the word “system” or similar words like
“technique” or “means” can encompass cap-and-trade, the Government
maintains, why not in Section 111?

															But just because a cap-and-trade “system” can be
used to reduce emissions does not mean that it is the kind of
“system of emission reduction” referred to in Section 111. Indeed,
the Government’s examples demonstrate why it is not.

															First, unlike Section 111, the Acid Rain and
NAAQS programs contemplate trading systems as a means of complying with an already established emissions
limit , set either directly by Congress (as with Acid Rain, see
42 U. S. C. §7651c) or by reference to the safe
concentration of the pollutant in the ambient air (as with the
NAAQS). In Section 111, by contrast, it is EPA’s job to come up
with the cap itself: the “numerical limit on emissions” that States
must apply to each source. 80 Fed. Reg. 64768. We doubt that
Congress directed the Agency to set an emissions cap at the level
“which reflects the degree of emission limitation achievable
through the application of [a cap-and-trade] system,” §7411(a)(1),
for that degree is indeterminate. It is one thing for Congress to
authorize regulated sources to use trading to comply with a preset
cap, or a cap that must be based on some scientific, objective
criterion, such as the NAAQS. It is quite another to simply
authorize EPA to set the cap itself wherever the Agency sees
fit.

															Second, Congress added the above authorizations
for the use of emissions trading programs in 1990, simultaneous
with amending Section 111 to its present form. At the time,
cap-and-trade was a novel and highly touted concept. The Acid Rain
program was “the nation’s first-ever emissions trading program.” L.
Heinzerling & R. Steinzor, A Perfect Storm: Mercury and the
Bush Administration, 34 Env. L. Rep. 10297, 10309 (2004). And
Congress went out of its way to amend the NAAQS statute to make
absolutely clear that the “measures, means, [and] techniques”
States could use to meet the NAAQS included cap-and-trade.
§7410(a)(2)(A). Yet “not a peep was heard from Congress about the
possibility that a trading regime could be installed under §111.” Id. , at 10309.

															Finally, the Government notes that other parts
of the Clean Air Act, past and present, have “explicitly limited
the permissible components of a particular ‘system’ ” of emission
reduction in some regard. Brief for Federal Respondents 32. For
instance, a separate section of the statute empowers EPA to require
the “degree of reduction achievable through the retrofit application of the best system of continuous emission
reduction.” §7651f(b)(2) (emphasis added). The comparatively
unadorned use of the phrase “best system of emission reduction” in
Section 111, the Government urges, “suggest[s] a conscious
congressional” choice not to limit the measures that may
constitute the BSER to those applicable at or to an individual
source. Id. , at 32 . These arguments, however, concern an
interpretive question that is not at issue. We have no occasion to
decide whether the statutory phrase “system of emission reduction”
refers exclusively to measures that improve the pollution
performance of individual sources, such that all other actions are
ineligible to qualify as the BSER. To be sure, it is pertinent to
our analysis that EPA has acted consistent with such a limitation
for the first four decades of the statute’s existence. But the only
interpretive question before us, and the only one we answer, is
more narrow: whether the “best system of emission reduction”
identified by EPA in the Clean Power Plan was within the authority
granted to the Agency in Section 111(d) of the Clean Air Act. For
the reasons given, the answer is no.[ 5 ]

															*  *  *

															Capping carbon dioxide emissions at a level
that will force a nationwide transition away from the use of coal
to generate electricity may be a sensible “solution to the crisis
of the day.” New York v. United States , 505 U.S.
144 , 187 (1992). But it is not plausible that Congress gave EPA
the authority to adopt on its own such a regulatory scheme in
Section 111(d). A decision of such magnitude and consequence rests
with Congress itself, or an agency acting pursuant to a clear
delegation from that representative body. The judgment of the Court
of Appeals for the District of Columbia Circuit is reversed, and
the cases are remanded for further proceedings consistent with this
opinion.

															It is so ordered. Notes 1 The dissent cites other
ostensible precedents, see post , at 25–26, but they are also
inapposite. A few allowed cap-and-trade or similar averaging
measures as compliance mechanisms, like the Mercury Rule. See, e.g. , 60 Fed. Reg. 65402 (1995). The others were not Section
111 rules. 2 See McGarity 165 (EPA
promulgates “technology-based new source performance standards that
require the implementation of the ‘best available demonstrated’
technology”); P. McCubbin, The Risk in Technology-Based Standards,
16 Duke Env. L. & Pol’y Forum 1, 46, n. 180 (2003)
(Section 111 standards “are another set of technology-based
standards”); W. Wagner, The Triumph of Technology-Based Standards,
2000 U. Ill. L. Rev 83, 84, n. 4 (“Technology-based
standards made their initial appearance” in “Section 111 of the
Clean Air Act,” which “requires the EPA to set technology-based
emission limitations”). The dissent points to a 1977 amendment to
Section 111 as evidence that the 1970 Congress did not intend for
EPA to establish this sort of source-specific standard. Post , at 10–11. But it is clear that the 1977 amendment was
merely intended to prohibit power plants from adopting one specific
kind of at-the-source measure—a switch from burning high-sulfur
coal to low-sulfur coal—and was not intended or understood to
change the basic, source-focused regulatory approach. See Wisconsin Elec. Power Co. v. Reilly , 893 F.2d 901,
919 (CA8 1990) (explaining the history); B. Ackerman & W.
Hassler, Clean Coal/Dirty Air (1981) (same). 3 The dissent suggests that
EPA could bring about the same result by, for example, simply
requiring coal plants to become natural gas plants, and that this
would fit within the prior regulatory approach of
efficiency-improving, at-the-source measures. Post , at 24.
Of course, EPA has never ordered anything remotely like that, and
we doubt it could. Section 111(d) empowers EPA to guide States in
“establish[ing] standards of performance” for “existing source[s],”
§7411(d)(1), not to direct existing sources to effectively cease to
exist. 4 According to the dissent, “EPA
is always controlling the mix of energy sources” under Section 111
because all of the Agency’s rules impose some costs on regulated
plants, and therefore (all else equal) cause those plants to lose
some share of the electricity market. Post, at 22. But there
is an obvious difference between (1) issuing a rule that may end up
causing an incidental loss of coal’s market share, and (2) simply
announcing what the market share of coal, natural gas, wind, and
solar must be, and then requiring plants to reduce operations or
subsidize their competitors to get there. No one has ever thought
that the Clean Power Plan was just business as usual. See American Lung Assn. v. EPA , 985 F.3d 914, 1000 (CADC
2021) (Walker, J., dissenting) (“Leaders of the environmental
movement considered the rule ‘groundbreaking,’ called its
announcement ‘historic,’ and labeled it a ‘critically important
catalyst.’ ” (footnotes omitted)). 5 We find it odd that the
dissent accuses us of champing at the bit to “constrain EPA’s
efforts to address climate change,” post , at 4, yet also
chides us for “mak[ing] no effort” to opine—in what would be plain
dicta—on “how far [our] opinion constrain[s] EPA,” post , at
12. SUPREME COURT OF THE UNITED STATES

															_________________

															Nos. 20–1530, 20–1531, 20–1778 and
20–1780

															_________________

															WEST VIRGINIA, et al.,
PETITIONERS

															20–1530 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															THE NORTH AMERICAN COAL CORPORATION,
PETITIONER

															20–1531 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															WESTMORELAND MINING HOLDINGS LLC,
PETITIONER

															20–1778 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															NORTH DAKOTA, PETITIONER

															20–1780 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															on writs of certiorari to the united states
court of appeals for the district of columbia circuit

															[June 30, 2022]

															Justice Gorsuch, with whom Justice Alito
joins, concurring.

															To resolve today’s case the Court invokes the
major questions doctrine. Under that doctrine’s terms,
administrative agencies must be able to point to “ ‘clear
congressional authorization’ ” when they claim the power to
make decisions of vast “ ‘economic and political
significance.’ ” Ante , at 17, 19. Like many parallel
clear-statement rules in our law, this one operates to protect
foundational constitutional guarantees. I join the Court’s opinion
and write to offer some additional observations about the doctrine
on which it rests.

															I

															A

															One of the Judiciary’s most solemn duties is
to ensure that acts of Congress are applied in accordance with the
Constitution in the cases that come before us. To help fulfill that
duty, courts have developed certain “clear-statement” rules. These
rules assume that, absent a clear statement otherwise, Congress
means for its laws to operate in congruence with the Constitution
rather than test its bounds. In this way, these clear-statement
rules help courts “act as faithful agents of the Constitution.” A.
Barrett, Substantive Canons and Faithful Agency, 90 B. U.
L. Rev. 109, 169 (2010) (Barrett).

															Consider some examples. The Constitution
prohibits Congress from passing laws imposing various types of
retroactive liability. See Art. I, § 9; Landgraf v. USI
Film Products , 511 U.S.
244 , 265–266 (1994). Consistent with this rule, Chief Justice
Marshall long ago advised that “a court . . . ought to
struggle hard against a [statutory] construction which will, by a
retrospective operation, affect the rights of parties.” United
States v. Schooner Peggy , 1 Cranch 103, 110 (1801).
Justice Paterson likewise insisted that courts must interpret
statutes to apply only prospectively “unless they are so clear,
strong, and imperative, that no other meaning can be annexed to
them.” United States v. Heth , 3 Cranch 399, 413
(1806).

															The Constitution also incorporates the doctrine
of sovereign immunity. See, e.g. , Hans v. Louisiana , 134 U.S.
1 , 12–17 (1890). To enforce that doctrine, courts have
consistently held that “nothing but express words, or an
insurmountable implication” would justify the conclusion that
lawmakers intended to abrogate the States’ sovereign immunity. Chisholm v. Georgia , 2 Dall. 419, 450 (1793)
(Iredell, J., dissenting); see Seminole Tribe of Fla. v. Florida , 517 U.S.
44 , 55 (1996). In a similar vein, Justice Story observed that
“[i]t is a general rule in the interpretation of legislative acts
not to construe them to embrace the sovereign power or government,
unless expressly named or included by necessary implication.” United States v. Greene , 26 F. Cas. 33, 34 (No. 15,
258) (CC Me. 1827).

															The major questions doctrine works in much the
same way to protect the Constitution’s separation of powers. Ante , at 19. In Article I, “the People” vested “[a]ll”
federal “legislative powers . . . in Congress.” Preamble;
Art. I, § 1. As Chief Justice Marshall put it, this means that
“important subjects . . . must be entirely regulated by
the legislature itself,” even if Congress may leave the Executive
“to act under such general provisions to fill up the details.” Wayman v. Southard , 10 Wheat. 1, 42–43 (1825).
Doubtless, what qualifies as an important subject and what
constitutes a detail may be debated. See, e.g. , Gundy v. United States , 588 U. S. ___, ___–___ (2019)
(plurality opinion) (slip op., at 4–6); id. , at ___–___
(Gorsuch, J., dissenting) (slip op., at 10–12). But no less than
its rules against retroactive legislation or protecting sovereign
immunity, the Constitution’s rule vesting federal legislative power
in Congress is “vital to the integrity and maintenance of the
system of government ordained by the Constitution.” Marshall
Field & Co. v. Clark , 143 U.S.
649 , 692 (1892).

															It is vital because the framers believed that a
republic—a thing of the people—would be more likely to enact just
laws than a regime administered by a ruling class of largely
unaccountable “ministers.” The Federalist No. 11, p. 85 (C.
Rossiter ed. 1961) (A. Hamilton). From time to time, some have
questioned that assessment.[ 1 ]
But by vesting the lawmaking power in the people’s elected
representatives, the Constitution sought to ensure “not only that
all power [w]ould be derived from the people,” but also “that those
[e]ntrusted with it should be kept in dependence on the people.” Id. , No. 37, at 227 (J. Madison). The Constitution, too,
placed its trust not in the hands of “a few, but [in] a number of
hands,” ibid. , so that those who make our laws would better
reflect the diversity of the people they represent and have an
“immediate dependence on, and an intimate sympathy with, the
people.” Id. , No. 52, at 327 (J. Madison). Today, some might
describe the Constitution as having designed the federal lawmaking
process to capture the wisdom of the masses. See P. Hamburger, Is
Administrative Law Unlawful? 502–503 (2014).

															Admittedly, lawmaking under our Constitution can
be difficult. But that is nothing particular to our time nor any
accident. The framers believed that the power to make new laws
regulating private conduct was a grave one that could, if not
properly checked, pose a serious threat to individual liberty. See
The Federalist No. 48, at 309–312 (J. Madison); see also id. , No. 73, at 441–442 (A. Hamilton). As a result, the
framers deliberately sought to make lawmaking difficult by
insisting that two houses of Congress must agree to any new law and
the President must concur or a legislative supermajority must
override his veto.

															The difficulty of the design sought to serve
other ends too. By effectively requiring a broad consensus to pass
legislation, the Constitution sought to ensure that any new laws
would enjoy wide social acceptance, profit from input by an array
of different perspectives during their consideration, and thanks to
all this prove stable over time. See id. , No. 10, at 82–84
(J. Madison). The need for compromise inherent in this design also
sought to protect minorities by ensuring that their votes would
often decide the fate of proposed legislation—allowing them to
wield real power alongside the majority. See id. , No. 51, at
322–324 (J. Madison). The difficulty of legislating at the federal
level aimed as well to preserve room for lawmaking “by governments
more local and more accountable than a distant federal” authority, National Federation of Independent Business v. Sebelius , 567 U.S.
519 , 536 (2012) (plurality opinion), and in this way allow
States to serve as “laborator[ies]” for “novel social and economic
experiments,” New State Ice Co . v. Liebmann , 285 U.S.
262 , 311 (1932) (Brandeis, J., dissenting); see J. Sutton, 51
Imperfect Solutions: States and the Making of American
Constitutional Law 11 (2018).

															Permitting Congress to divest its legislative
power to the Executive Branch would “dash [this] whole scheme.” Department of Transportation v. Association of American
Railroads , 575 U.S. 43, 61 (2015) (Alito, J., concurring).
Legislation would risk becoming nothing more than the will of the
current President, or, worse yet, the will of unelected officials
barely responsive to him. See S. Breyer, Making Our Democracy
Work: A Judge’s View 110 (2010) (“[T]he president may not have the
time or willingness to review [agency] decisions”). In a world like
that, agencies could churn out new laws more or less at whim.
Intrusions on liberty would not be difficult and rare, but easy and
profuse. See The Federalist No. 47, at 303 (J. Madison); id. , No. 62, at 378 (J. Madison). Stability would be lost,
with vast numbers of laws changing with every new presidential
administration. Rather than embody a wide social consensus and
input from minority voices, laws would more often bear the support
only of the party currently in power. Powerful special interests,
which are sometimes “uniquely” able to influence the agendas of
administrative agencies, would flourish while others would be left
to ever-shifting winds. T. Merrill, Capture Theory and the Courts:
1967–1983, 72 Chi.-Kent L. Rev. 1039, 1043 (1997). Finally,
little would remain to stop agencies from moving into areas where
state authority has traditionally predominated. See, e.g. , Solid Waste Agency of Northern Cook Cty. v. Army Corps of
Engineers , 531 U.S.
159 , 173–174 (2001) ( SWANC ). That would be a
particularly ironic outcome, given that so many States have robust
nondelegation doctrines designed to ensure democratic
accountability in their state lawmaking processes. See R. May, The
Nondelegation Doctrine is Alive and Well in the States, The Reg.
Rev. (Oct. 15, 2020).

															B

															Much as constitutional rules about retroactive
legislation and sovereign immunity have their corollary
clear-statement rules, Article I’s Vesting Clause has its own: the
major questions doctrine. See Gundy , 588 U. S., at
___–___ (Gorsuch, J., dissenting) (slip op., at 20–21). Some
version of this clear-statement rule can be traced to at least
1897, when this Court confronted a case involving the Interstate
Commerce Commission, the federal government’s “first modern
regulatory agency.” S. Dudley, Milestones in the Evolution of the
Administrative State 3 (Nov. 2020). The ICC argued that Congress
had endowed it with the power to set carriage prices for railroads.
See ICC v. Cincinnati, N. O. & T. P. R. Co. , 167 U.S.
479 , 499 (1897). The Court deemed that claimed authority “a
power of supreme delicacy and importance,” given the role railroads
then played in the Nation’s life. Id. , at 505. Therefore,
the Court explained, a special rule applied:

															“That Congress has transferred such a
power to any administrative body is not to be presumed or implied
from any doubtful and uncertain language. The words and phrases
efficacious to make such a delegation of power are well understood,
and have been frequently used, and if Congress had intended to
grant such a power to the [agency], it cannot be doubted that it
would have used language open to no misconstruction , but clear and direct .” Ibid. (emphasis added) . With the explosive growth of the administrative
state since 1970, the major questions doctrine soon took on special
importance.[ 2 ] In 1980, this
Court held it “unreasonable to assume” that Congress gave an agency
“unprecedented power[s]” in the “absence of a clear [legislative]
mandate.” Industrial Union Dept., AFL–CIO v. American
Petroleum Institute , 448 U.S.
607 , 645 (plurality opinion). In the years that followed, the
Court routinely enforced “the nondelegation doctrine” through “the
interpretation of statutory texts, and, more particularly, [by]
giving narrow constructions to statutory delegations that might
otherwise be thought to be unconstitutional.” Mistretta v. United States , 488 U.S.
361 , 373, n. 7 (1989). In fact, this Court applied the
major questions doctrine in “all corners of the administrative
state,” whether the issue at hand involved an agency’s asserted
power to regulate tobacco products, ban drugs used in
physician-assisted suicide, extend Clean Air Act regulations to
private homes, impose an eviction moratorium, or enforce a vaccine
mandate. Ante , at 17; see FDA v. Brown &
Williamson Tobacco Corp ., 529 U.S.
120 , 160 (2000); Gonzales v. Oregon , 546 U.S.
243 , 267 (2006); Utility Air Regulatory Group v. EPA , 573 U.S.
302 , 324 (2014); Alabama Assn. of Realtors v. Department of Health and Human Servs. , 594 U. S. ___,
___ (2021) ( per curiam ) (slip op., at 6); National
Federation of Independent Business v. OSHA , 595
U. S. ___, ___ (2022) ( per curiam ) (slip op.,
at 6).[ 3 ]

															The Court has applied the major questions
doctrine for the same reason it has applied other similar
clear-statement rules—to ensure that the government does “not
inadvertently cross constitutional lines.” Barrett 175. And the
constitutional lines at stake here are surely no less important
than those this Court has long held sufficient to justify parallel
clear-statement rules. At stake is not just a question of
retroactive liability or sovereign immunity, but basic questions
about self-government, equality, fair notice, federalism, and the
separation of powers. See Part I–A, supra . The major
questions doctrine seeks to protect against “unintentional,
oblique, or otherwise unlikely” intrusions on these interests. NFIB v. OSHA , 595 U. S., at ___ (Gorsuch, J.,
concurring) (slip op., at 5). The doctrine does so by ensuring
that, when agencies seek to resolve major questions, they at least
act with clear congressional authorization and do not “exploit some
gap, ambiguity, or doubtful expression in Congress’s statutes to
assume responsibilities far beyond” those the people’s
representatives actually conferred on them. Ibid. As the
Court aptly summarizes it today, the doctrine addresses “a
particular and recurring problem: agencies asserting highly
consequential power beyond what Congress could reasonably be
understood to have granted.” Ante , at 20.

															II

															A

															Turning from the doctrine’s function to its
application, it seems to me that our cases supply a good deal of
guidance about when an agency action involves a major question for
which clear congressional authority is required. First , this Court has indicated that
the doctrine applies when an agency claims the power to resolve a
matter of great “political significance,” NFIB v. OSHA , 595 U. S., at ___ (slip op., at 6) (internal
quotation marks omitted), or end an “earnest and profound debate
across the country,” Gonzales , 546 U. S., at 267–268
(internal quotation marks omitted); see ante , at 17. So, for
example, in Gonzales , the Court found that the doctrine
applied when the Attorney General issued a regulation that would
have effectively banned most forms of physician-assisted suicide
even as certain States were considering whether to permit the
practice. 546 U. S., at 267. And in NFIB v. OSHA , the Court held the doctrine applied when an agency
sought to mandate COVID–19 vaccines nationwide for most workers at
a time when Congress and state legislatures were engaged in robust
debates over vaccine mandates. 595 U. S., at ___ (slip op., at
5); id. , at ___ (Gorsuch, J., concurring) (slip op., at 3).
Relatedly, this Court has found it telling when Congress has
“ ‘considered and rejected’ ” bills authorizing something
akin to the agency’s proposed course of action. Ante , at 20,
27 (quoting Brown & Williamson , 529 U. S., at 144).
That too may be a sign that an agency is attempting to “ ‘work
[a]round’ ” the legislative process to resolve for itself a
question of great political significance. NFIB v. OSHA , 595 U. S., at ___ (Gorsuch, J., concurring) (slip
op., at 3).[ 4 ] Second , this Court has said that an
agency must point to clear congressional authorization when it
seeks to regulate “ ‘a significant portion of the American
economy,’ ” ante , at 18 (quoting Utility Air ,
573 U. S., at 324), or require “billions of dollars in
spending” by private persons or entities, King v. Burwell , 576 U.S. 473, 485 (2015). The Court has held that
regulating tobacco products, eliminating rate regulation in the
telecommunications industry, subjecting private homes to Clean Air
Act restrictions, and suspending local housing laws and regulations
can sometimes check this box. See Brown & Williamson ,
529 U. S., at 160; MCI Telecommunications Corp. v. American Telephone & Telegraph Co. , 512 U.S.
218 , 231 (1994) ( MCI ); Utility Air , 573
U. S., at 324; Alabama Assn. of Realtors , 594
U. S., at ___ (slip op., at 6). Third , this Court has said that the major
questions doctrine may apply when an agency seeks to “intrud[e]
into an area that is the particular domain of state law.” Ibid . Of course, another longstanding clear-statement
rule—the federalism canon—also applies in these situations. To
preserve the “proper balance between the States and the Federal
Government” and enforce limits on Congress’s Commerce Clause power,
courts must “ ‘be certain of Congress’s intent’ ” before
finding that it “legislate[d] in areas traditionally regulated by
the States.” Gregory v. Ashcroft , 501 U.S.
452 , 459–460 (1991). But unsurprisingly, the major questions
doctrine and the federalism canon often travel together. When an
agency claims the power to regulate vast swaths of American life,
it not only risks intruding on Congress’s power, it also risks
intruding on powers reserved to the States. See SWANC , 531
U. S., at 162, 174.

															While this list of triggers may not be
exclusive, each of the signs the Court has found significant in the
past is present here, making this a relatively easy case for the
doctrine’s application. The EPA claims the power to force coal and
gas-fired power plants “to cease [operating] altogether.” Ante , at 24. Whether these plants should be allowed to
operate is a question on which people today may disagree, but it is
a question everyone can agree is vitally important. See ante , at 24–25. Congress has debated the matter frequently. Ibid. ; see generally Climate Change, The History of a
Consensus and the Causes of Inaction, Hearing before the
Subcommittee on Environment of the House Committee on Oversight and
Reform, 116th Cong., 1st Sess., pt. I (2019). And so far it has
“conspicuously and repeatedly declined” to adopt legislation
similar to the Clean Power Plan (CPP). Ante , at 20; see American Lung Assn. v. EPA , 985 F.3d 914, 998,
n. 19 (CADC 2021) (Walker, J., concurring in part, concurring
in judgment in part, and dissenting in part) (cataloguing failed
legislative proposals); cf. Brown & Williamson , 529
U. S., at 144. It seems that fact has frustrated the Executive
Branch and led it to attempt its own regulatory solution in the
CPP. See 985 F. 3d, at 998, n. 20 (President stating that
“ ‘if Congress won’t act soon . . . I will’ ”); cf. United States Telecom Assn. v. FCC , 855 F.3d 381,
423–424 (CADC 2017) (Kavanaugh, J., dissenting from denial of
rehearing en banc) (noting a “President’s intervention [may]
underscor[e] the enormous significance” of a regulation).

															Other suggestive factors are present too. “The
electric power sector is among the largest in the U. S.
economy, with links to every other sector.” N. Richardson,
Keeping Big Cases From Making Bad Law: The Resurgent “Major
Questions” Doctrine, 49 Conn. L. Rev. 355, 388 (2016). The
Executive Branch has acknowledged that its proposed rule would
force an “aggressive transformation” of the electricity sector
through “transition to zero-carbon renewable energy sources.” White
House Fact Sheet, App. in American Lung Assn. v. EPA ,
No. 19–1140 (CADC), pp. 2076–2077. The Executive Branch has also
predicted its rule would force dozens of power plants to close and
eliminate thousands of jobs by 2025. See EPA, Regulatory Impact
Analysis for the Clean Power Plan Final Rule 3–27, 3–30, 3–33, 6–25
(Oct. 23, 2015). And industry analysts have estimated the CPP would
cause consumers’ electricity costs to rise by over $200 billion.
See National Mining Assn., EPA’s Clean Power Plan: An Economic
Impact Analysis 2, 4 (2015). Finally, the CPP unquestionably has an
impact on federalism, as “the regulation of utilities is one of the
most important of the functions traditionally associated with the
police power of the States.” Arkansas Elec. Cooperative
Corp. v. Arkansas Pub. Serv. Comm’n , 461 U.S.
375 , 377 (1983). None of this is to say the policy the agency
seeks to pursue is unwise or should not be pursued. It is only to
say that the agency seeks to resolve for itself the sort of
question normally reserved for Congress. As a result, we look for
clear evidence that the people’s representatives in Congress have
actually afforded the agency the power it claims.

															B

															At this point, the question becomes what
qualifies as a clear congressional statement authorizing an
agency’s action. Courts have long experience applying
clear-statement rules throughout the law, and our cases have
identified several telling clues in this context too. First , courts must look to the
legislative provisions on which the agency seeks to rely
“ ‘with a view to their place in the overall statutory
scheme.’ ” Brown & Williamson , 529 U. S., at
133. “[O]blique or elliptical language” will not supply a clear
statement. Ante , at 18; see Spector v. Norwegian
Cruise Line Ltd. , 545 U.S.
119 , 139 (2005) (plurality opinion) (cautioning against
reliance on “broad or general language”). Nor may agencies seek to
hide “elephants in mouseholes,” Whitman v. American
Trucking Assns., Inc. , 531 U.S.
457 , 468 (2001), or rely on “gap filler” provisions, ante , at 20. So, for example, in MCI this Court
rejected the Federal Communication Commission’s attempt to
eliminate rate regulation for the telecommunications industry based
on a “subtle” provision that empowered the FCC to
“ ‘modify’ ” rates. 512 U. S., at 231. In Brown
& Williamson , the Court rejected the Food and Drug
Administration’s attempt to regulate cigarettes based a “cryptic”
statutory provision that granted the agency the power to regulate
“drugs” and “devices.” 529 U. S., at 126, 156, 160. And in Gonzales , the Court doubted that Congress gave the Attorney
General “broad and unusual authority” to regulate drugs for
physician-assisted suicide through “oblique” statutory language.
546 U. S., at 267. Second , courts may examine the age and
focus of the statute the agency invokes in relation to the problem
the agency seeks to address. As the Court puts it today, it is
unlikely that Congress will make an “[e]xtraordinary gran[t] of
regulatory authority” through “vague language” in “ ‘a
long-extant statute.’ ” Ante , at 18–20 (quoting Utility Air , 573 U. S., at 324). Recently, too, this
Court found a clear statement lacking when OSHA sought to impose a
nationwide COVID–19 vaccine mandate based on a statutory provision
that was adopted 40 years before the pandemic and that focused on
conditions specific to the workplace rather than a problem faced by
society at large. See NFIB v. OSHA , 595 U. S.,
at ___ (Gorsuch, J., concurring) (slip op., at 3). Of course,
sometimes old statutes may be written in ways that apply to new and
previously unanticipated situations. See Sedima,
S. P. R. L. v. Imrex Co. , 473 U.S.
479 , 499 (1985). But an agency’s attempt to deploy an old
statute focused on one problem to solve a new and different problem
may also be a warning sign that it is acting without clear
congressional authority. See ante , at 18. Third , courts may examine the agency’s
past interpretations of the relevant statute. See ante , at
20–21. A “contemporaneous” and long-held Executive Branch
interpretation of a statute is entitled to some weight as evidence
of the statute’s original charge to an agency. United States v. Philbrick , 120 U.S.
52 , 59 (1887). Conversely, in NFIB v. OSHA , the
Court found it “telling that OSHA, in its half century of
existence, ha[d] never before adopted a broad public health
regulation” under the statute that the agency sought to invoke as
authority for a nationwide vaccine mandate. 595 U. S., at ___
(slip op., at 8); ante , at 18; see also Brown &
Williamson , 529 U. S., at 158–159 (noting that for decades
the FDA had said it lacked statutory power to regulate cigarettes).
As the Court states today, “ ‘the want of [an] assertion of
power by those who presumably would be alert’ ” to it is
“ ‘significant in determining whether such power was actually
conferred.’ ” Ante , at 21. When an agency claims to
have found a previously “unheralded power,” its assertion generally
warrants “a measure of skepticism.” Utility Air , 573
U. S., at 324. Fourth , skepticism may be merited when
there is a mismatch between an agency’s challenged action and its
congressionally assigned mission and expertise. Ante , at 25.
As the Court explains, “[w]hen an agency has no comparative
expertise in making certain policy judgments, . . .
Congress presumably would not task it with doing so.” Ibid. (internal quotation marks and alterations omitted). So, for
example, in Alabama Assn. of Realtors , this Court rejected
an attempt by a public health agency to regulate housing. 594
U. S., at ___ (slip op., at 5). And in NFIB v. OSHA , the Court rejected an effort by a workplace safety
agency to ordain “broad public health measures” that “f[ell]
outside [its] sphere of expertise.” 595 U. S., at ___ (slip
op., at 6).[ 5 ]

															Asking these questions again yields a clear
answer in our case. See ante , at 28–31. As the Court
details, the agency before us cites no specific statutory authority
allowing it to transform the Nation’s electrical power supply. See ante , at 28. Instead, the agency relies on a rarely invoked
statutory provision that was passed with little debate and has been
characterized as an “obscure, never-used section of the law.” Ante , at 6 (internal quotation marks omitted). Nor has the
agency previously interpreted the relevant provision to confer on
it such vast authority; there is no original, longstanding, and
consistent interpretation meriting judicial respect. See ante , at 20–22. Finally, there is a “mismatch” between the
EPA’s expertise over environmental matters and the agency’s claim
that “Congress implicitly tasked it, and it alone, with balancing
the many vital considerations of national policy implicated in
deciding how Americans will get their energy.” Ante , at 25.
Such a claimed power “requires technical and policy expertise not traditionally needed in [the] EPA’s regulatory
development.” Ibid. (internal quotation marks omitted).
Again, in observing this much, the Court does not purport to pass
on the wisdom of the agency’s course. It acknowledges only that
agency officials have sought to resolve a major policy question
without clear legislative authorization to do so.

															III

															In places, the dissent seems to suggest that
we should not be unduly “ ‘concerned’ ” with the
Constitution’s assignment of the legislative power to Congress. Post , at 29 (opinion of Kagan, J.). Echoing Woodrow Wilson,
the dissent seems to think “a modern Nation” cannot afford such
sentiments. Post , at 29–31. But recently, our dissenting
colleagues acknowledged that the Constitution assigns “all
legislative Powers” to Congress and “bar[s their] further
delegation.” Gundy , 588 U. S., at ___ (plurality
opinion of Kagan, J.) (slip op., at 4) (internal quotation marks
and alteration omitted). To be sure, in that case we disagreed
about the exact nature of the “nondelegation inquiry” courts must
employ to vindicate the Constitution. Id. , at ___ (slip op.,
at 5). But like Chief Justice Marshall, we all recognized that the
Constitution does impose some limits on the delegation of
legislative power. See ibid. ; Wayman , 10 Wheat., at
42–43. And while we all agree that administrative agencies have
important roles to play in a modern nation, surely none of us
wishes to abandon our Republic’s promise that the people and their
representatives should have a meaningful say in the laws that
govern them. Cf. Rucho v. Common Cause , 588
U. S. ___, ___ (2019) (Kagan, J., dissenting) (slip op., at 7)
(“Republican liberty demands not only, that all power should be
derived from the people; but that those entrusted with it should be
kept in dependence on the people” (internal quotation marks and
alteration omitted)) . [ 6 ]

															So what is our real point of disagreement? The
dissent next suggests that the Court strays from its commitment to
textualism by relying on a clear-statement rule (the major
questions doctrine) to resolve today’s case. Post , at 28.
But our law is full of clear-statement rules and has been since the
founding. Our colleagues do not dispute the point. In fact, they
have regularly invoked many of these rules.[ 7 ]

															If that’s not the problem, perhaps the dissent
means to suggest that the major questions doctrine does not belong
on the list of our clear-statement rules. At times, the dissent
appears to dismiss the doctrine as a “get-out-of-text free car[d].” Ibid . The dissent even seems to suggest that the doctrine
could threaten “the safety and efficacy of medications” or lead to
“the routine adulteration of food.” Post , at 31. But then
again, the dissent also acknowledges that the major questions
doctrine should “sensibl[y]” apply in at least some situations. Post , at 14–15. The dissent even favorably highlights one
application of the doctrine that our colleagues criticized less
than a year ago. See post , at 18 (citing Alabama Assn. of
Realtors , 594 U. S. ___). And, of course, our colleagues
have joined other applications of the major questions doctrine in
the past. See, e.g. , King , 576 U. S., at
485–486; Gonzales , 546 U. S., at 267–268. Nor does the
dissent really seem to dispute that a major question is at stake in
this case. As the dissent observes, the agency’s challenged action
before us concerns one of “the greatest . . .
challenge[s] of our time.” Post , at 21. If this case does
not implicate a “question of deep economic and political
significance,” King , 576 U. S., at 486 (internal
quotation marks omitted), it is unclear what might.[ 8 ]

															In the end, our disagreement really seems to
center on a difference of opinion about whether the statute at
issue here clearly authorizes the agency to adopt the CPP. The
dissent even complains that I have failed to conduct an exhaustive
analysis of the relevant statutory language. See post , at
28, n. 8. But in this concurrence, I have sought to provide
some observations about the underlying doctrine on which today’s
decision rests. On the merits of the case before us, I join the
Court’s opinion, which comprehensively sets forth why Congress did
not clearly authorize the EPA to engage in a “generation shifting
approach” to the production of energy in this country. Ante ,
at 28. In reaching its judgment, the Court hardly professes to
“appoin[t] itself” “the decision-maker on climate policy.” Post , at 33. The Court acknowledges only that, under our
Constitution, the people’s elected representatives in Congress are
the decisionmakers here—and they have not clearly granted the
agency the authority it claims for itself. Ante , at 31.

															*

															When Congress seems slow to solve problems, it
may be only natural that those in the Executive Branch might seek
to take matters into their own hands. But the Constitution does not
authorize agencies to use pen-and-phone regulations as substitutes
for laws passed by the people’s representatives. In our Republic,
“[i]t is the peculiar province of the legislature to prescribe
general rules for the government of society.” Fletcher v. Peck , 6 Cranch 87, 136 (1810). Because today’s decision
helps safeguard that foundational constitutional promise, I am
pleased to concur. Notes 1 For example, Woodrow
Wilson famously argued that “popular sovereignty” “embarrasse[d]”
the Nation because it made it harder to achieve “executive
expertness.” The Study of Administration, 2 Pol. Sci. Q. 197, 207
(1887) (Administration). In Wilson’s eyes, the mass of the people
were “selfish, ignorant, timid, stubborn, or foolish.” Id. ,
at 208. He expressed even greater disdain for particular groups,
defending “[t]he white men of the South” for “rid[ding] themselves,
by fair means or foul, of the intolerable burden of governments
sustained by the votes of ignorant [African-Americans].” 9 W.
Wilson, History of the American People 58 (1918). He likewise
denounced immigrants “from the south of Italy and men of the meaner
sort out of Hungary and Poland,” who possessed “neither skill nor
energy nor any initiative of quick intelligence.” 5 id. , at
212. To Wilson, our Republic “tr[ied] to do too much by vote.”
Administration 214. 2 In the 1960s and 1970s,
Congress created dozens of new federal administrative agencies. See
W. Howell & D. Lewis, Agencies by Presidential Design, 64 J. of
Politics 1095, 1105 (Nov. 2002). Between 1970 and 1990, the Code of
Federal Regulations grew from about 44,000 pages to about 106,000.
See C. DeMuth, Can the Administrative State be Tamed?, 8 J. Legal
Analysis 121, 126 (Feb. 2016). Today, Congress issues “roughly two
hundred to four hundred laws” every year, while “federal
administrative agencies adopt something on the order of three
thousand to five thousand final rules.” R. Cass, Rulemaking Then
and Now: From Management to Lawmaking, 28 Geo. Mason L. Rev.
683, 694 (2021). Beyond that, agencies regularly “produce
thousands, if not millions,” of guidance documents which, as a
practical matter, bind affected parties too. See
C. Coglianese, Illuminating Regulatory Guidance, 9 Mich. J.
Env. & Admin. L. 243, 247–248 (2020). 3 At times, this Court
applied the major questions doctrine more like an ambiguity canon.
See FDA v. Brown & Williamson Tobacco Corp. , 529 U.S.
120 , 159 (2000). Ambiguity canons merely instruct courts on how
to “choos[e] between equally plausible interpretations of ambiguous
text,” and are thus weaker than clear-statement rules. Barrett 109.
But our precedents have usually applied the doctrine as a
clear-statement rule, and the Court today confirms that is the
proper way to apply it. See ante , at 19–20, 28. 4 In the dissent’s view,
the Court has erred both today and in the past by pointing to
failed legislation. Post , at 27–28 (opinion of Kagan, J.).
But the Court has not pointed to failed legislation to resolve what
a duly enacted statutory text means, only to help resolve the
antecedent question whether the agency’s challenged action
implicates a major question. The dissent endorses looking to
extrinsic evidence to resolve that question too. See post ,
at 21–22 (discussing whether there is a “mismatch” between an
agency’s expertise and its challenged action). 5 The dissent not only
agrees that a mismatch between an agency’s expertise and its
challenged action is relevant to the major questions doctrine
analysis; the dissent suggests that such a mismatch is necessary to
the doctrine’s application. See post , at 14–15. But this
Court has never taken that view. See, e.g. , ICC v. Cincinnati, N. O. & T. P. R. Co. , 167 U.S.
479 , 505 (1897) (interstate commerce agency regulating
interstate railroad commerce); Industrial Union Dept.,
AFL–CIO v. American Petroleum Institute , 448 U.S.
607 , 645 (1980) (plurality opinion) (workplace safety agency
regulating workplace carcinogens); Brown & Williamson ,
529 U. S., at 159–160 (drug agency regulating tobacco); King v. Burwell , 576 U.S. 473, 485–486 (2015) (tax
agency administering tax credits). 6 In the course of its
argument, the dissent leans heavily on two recent academic
articles. Post , at 29. But if a battle of law reviews were
the order of the day, it might be worth adding to the reading list.
See, e.g. , I. Wurman, Nondelegation at the Founding, 130
Yale L. J. 1490, 1493–1494 (2021); D. Candeub, Preference and
Administrative Law, 72 Admin. L. Rev. 607, 614–628 (2020); P.
Hamburger, Delegation or Divesting?, 115 Nw. L. Rev. Online 88,
91–110 (2020); M. McConnell, The President Who Would Not Be King
326–335 (2020); A. Gordon, Nondelegation, 12 N. Y. U. J. L. &
Liberty 718, 719 (2019); R. Cass, Delegation Reconsidered: A
Delegation Doctrine for the Modern Administrative State, 40 Harv.
J. L. & Pub. Pol’y 147, 155–161 (2017); G. Lawson & G.
Seidman, “A Great Power of Attorney:” Understanding the Fiduciary
Constitution 104–129 (2017); P. Hamburger, Is Administrative Law
Unlawful? 377–402 (2014); L. Alexander & S. Prakash, Reports of
the Nondelegation Doctrine’s Death are Greatly Exaggerated, 70 U.
Chi. L. Rev. 1297, 1298–1299 (2003); G. Lawson, Delegation and
Original Meaning, 88 Va. L. Rev. 327, 335–343 (2002); D.
Schoenbrod, The Delegation Doctrine: Could the Court Give It
Substance? 83 Mich. L. Rev. 1223, 1252–1255, 1260–1261 (1985);
see generally P. Wallison & J. Yoo, The Administrative State
Before the Supreme Court: Perspectives on the Nondelegation
Doctrine (2022). 7 See, e.g. , United States v. Washington , 596 U. S. ___, ___
(2022) (slip op., at 6) (intergovernmental immunity); Rehaif v. United States , 588 U. S. ___, ___ (2019) (slip op.,
at 3) ( mens rea ); Michigan v. Bay Mills Indian
Community , 572 U.S.
782 , 790–791 (2014) (sovereign immunity); Vartelas v. Holder , 566 U.S.
257 , 261, 266–267 (2012) (retroactivity); Gonzalez v. Thaler , 565 U.S.
134 , 141–142 (2012) (presumption against rule being
jurisdictional); Smith v. Bayer Corp. , 564 U.S.
299 , 307 (2011) (presumption that federal injunctions don’t bar
parallel state proceedings); Fowler v. United States , 563 U.S.
668 , 677 (2011) (federalism canon); Kucana v. Holder , 558 U.S.
233 , 237 (2010) (presumption in favor of judicial review); Holland v. Florida , 560 U.S.
631 , 645–646 (2010) (presumption in favor of equitable
tolling); Hamilton v. Lanning , 560 U.S.
505 , 517 (2010) (presumption that Bankruptcy Code didn’t erode
past practice). 8 The dissent seeks to
invoke Justice Scalia as authority against the major questions
doctrine. See post , at 31–32. But the dissent neglects to
mention that Justice Scalia authored or joined several of the
Court’s major questions decisions, including Brown &
Williamson , which the dissent describes as the “key case.” Post , at 15–16 (citing 529 U. S. 120); see also Whitman v. American Trucking Assns. , Inc. , 531 U.S.
457 , 468 (2001); Utility Air , 573 U. S., at 307; A.
Scalia, A Note on the Benzene Case, American Enterprise Institute,
J. on Govt. & Soc., July–Aug. 1980,
pp. 27–28. SUPREME COURT OF THE UNITED STATES

															_________________

															Nos. 20–1530, 20–1531, 20–1778 and
20–1780

															_________________

															WEST VIRGINIA, et al.,
PETITIONERS

															20–1530 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															THE NORTH AMERICAN COAL CORPORATION,
PETITIONER

															20–1531 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															WESTMORELAND MINING HOLDINGS LLC,
PETITIONER

															20–1778 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															NORTH DAKOTA, PETITIONER

															20–1780 v. ENVIRONMENTAL PROTECTION AGENCY,
et al.

															on writs of certiorari to the united states
court of appeals for the district of columbia circuit

															[June 30, 2022]

															Justice Kagan, with whom Justice Breyer and
Justice Sotomayor join, dissenting.

															Today, the Court strips the Environmental
Protection Agency (EPA) of the power Congress gave it to respond to
“the most pressing environmental challenge of our time.” Massachusetts v. EPA , 549 U.S.
497 , 505 (2007).

															Climate change’s causes and dangers are no
longer subject to serious doubt. Modern science is “unequivocal
that human influence”—in particular, the emission of greenhouse
gases like carbon dioxide—“has warmed the atmosphere, ocean and
land.” Intergovernmental Panel on Climate Change, Sixth Assessment
Report, The Physical Science Basis: Headline Statements 1 (2021).
The Earth is now warmer than at any time “in the history of modern
civilization,” with the six warmest years on record all occurring
in the last decade. U. S. Global Change Research Program,
Fourth National Climate Assessment, Vol. I, p. 10 (2017);
Brief for Climate Scientists as Amici Curiae 8. The rise in
temperatures brings with it “increases in heat-related deaths,”
“coastal inundation and erosion,” “more frequent and intense
hurricanes, floods, and other extreme weather events,” “drought,”
“destruction of ecosystems,” and “potentially significant
disruptions of food production.” American Elec. Power Co. v. Connecticut , 564 U.S.
410 , 417 (2011) (internal quotation marks omitted). If the
current rate of emissions continues, children born this year could
live to see parts of the Eastern seaboard swallowed by the ocean.
See Brief for Climate Scientists as Amici Curiae 6. Rising
waters, scorching heat, and other severe weather conditions could
force “mass migration events[,] political crises, civil unrest,”
and “even state failure.” Dept. of Defense, Climate Risk Analysis 8
(2021). And by the end of this century, climate change could be the
cause of “4.6 million excess yearly deaths.” See R. Bressler, The
Mortality Cost of Carbon, 12 Nature Communications 4467, p. 5
(2021).

															Congress charged EPA with addressing those
potentially catastrophic harms, including through regulation of
fossil-fuel-fired power plants. Section 111 of the Clean Air Act
directs EPA to regulate stationary sources of any substance that
“causes, or contributes significantly to, air pollution” and that
“may reasonably be anticipated to endanger public health or
welfare.” 42 U. S. C. §7411(b)(1)(A). Carbon dioxide and
other greenhouse gases fit that description. See American Elec.
Power , 564 U. S., at 416–417; Massachusetts , 549
U. S., at 528–532. EPA thus serves as the Nation’s “primary
regulator of greenhouse gas emissions.” American Elec.
Power , 564 U. S., at 428. And among the most significant
of the entities it regulates are fossil-fuel-fired (mainly coal-
and natural-gas-fired) power plants. Today, those
electricity-producing plants are responsible for about one quarter
of the Nation’s greenhouse gas emissions. See EPA, Sources of
Greenhouse Gas Emissions (Apr. 14, 2022),
https://www.epa.gov/ghgemissions/sources-greenhouse- gas-emissions.
Curbing that output is a necessary part of any effective approach
for addressing climate change.

															To carry out its Section 111 responsibility, EPA
issued the Clean Power Plan in 2015. The premise of the Plan—which
no one really disputes—was that operational improvements at the
individual-plant level would either “lead to only small emission
reductions” or would cost far more than a readily available
regulatory alternative. 80 Fed. Reg. 64727–64728 (2015). That
alternative—which fossil-fuel-fired plants were “already using to
reduce their [carbon dioxide] emissions” in “a cost effective
manner”—is called generation shifting. Id. , at 64728, 64769.
As the Court explains, the term refers to ways of shifting
electricity generation from higher emitting sources to lower
emitting ones—more specifically, from coal-fired to
natural-gas-fired sources, and from both to renewable sources like
solar and wind. See ante , at 8. A power company (like the
many supporting EPA here) might divert its own resources to a
cleaner source, or might participate in a cap-and-trade system with
other companies to achieve the same emissions-reduction goals.

															This Court has obstructed EPA’s effort from the
beginning. Right after the Obama administration issued the Clean
Power Plan, the Court stayed its implementation. That action was
unprecedented: Never before had the Court stayed a regulation then
under review in the lower courts. See Reply Brief for 29 States and
State Agencies in No. 15A773, p. 33 (conceding the point). The
effect of the Court’s order, followed by the Trump administration’s
repeal of the rule, was that the Clean Power Plan never went into
effect. The ensuing years, though, proved the Plan’s moderation.
Market forces alone caused the power industry to meet the Plan’s
nationwide emissions target—through exactly the kinds of generation
shifting the Plan contemplated. See 84 Fed. Reg. 32561–32562
(2019); Brief for United States 47. So by the time yet another
President took office, the Plan had become, as a practical matter,
obsolete. For that reason, the Biden administration announced that,
instead of putting the Plan into effect, it would commence a new
rulemaking. Yet this Court determined to pronounce on the legality
of the old rule anyway. The Court may be right that doing so does
not violate Article III mootness rules (which are notoriously
strict). See ante , at 14–16. But the Court’s docket is
discretionary, and because no one is now subject to the Clean Power
Plan’s terms, there was no reason to reach out to decide this case.
The Court today issues what is really an advisory opinion on the
proper scope of the new rule EPA is considering. That new rule will
be subject anyway to immediate, pre-enforcement judicial review.
But this Court could not wait—even to see what the new rule says—to
constrain EPA’s efforts to address climate change.

															The limits the majority now puts on EPA’s
authority fly in the face of the statute Congress wrote. The
majority says it is simply “not plausible” that Congress enabled
EPA to regulate power plants’ emissions through generation
shifting. Ante , at 31. But that is just what Congress did
when it broadly authorized EPA in Section 111 to select the “best
system of emission reduction” for power plants. §7411(a)(1). The
“best system” full stop—no ifs, ands, or buts of any kind relevant
here. The parties do not dispute that generation shifting is indeed
the “best system”—the most effective and efficient way to reduce
power plants’ carbon dioxide emissions. And no other provision in
the Clean Air Act suggests that Congress meant to foreclose EPA
from selecting that system; to the contrary, the Plan’s regulatory
approach fits hand-in-glove with the rest of the statute. The
majority’s decision rests on one claim alone: that generation
shifting is just too new and too big a deal for Congress to have
authorized it in Section 111’s general terms. But that is wrong. A
key reason Congress makes broad delegations like Section 111 is so
an agency can respond, appropriately and commensurately, to new and
big problems. Congress knows what it doesn’t and can’t know when it
drafts a statute; and Congress therefore gives an expert agency the
power to address issues—even significant ones—as and when they
arise. That is what Congress did in enacting Section 111. The
majority today overrides that legislative choice. In so doing, it
deprives EPA of the power needed—and the power granted—to curb the
emission of greenhouse gases.

															I

															The Clean Air Act was major legislation,
designed to deal with a major public policy issue. As Congress
explained, its goal was to “speed up, expand, and intensify the war
against air pollution” in all its forms. H. R. Rep. No.
91–1146, p. 1 (1970). Or as this Court similarly recognized,
the Act was a “drastic remedy to what was perceived as a serious
and otherwise uncheckable problem.” Union Elec. Co. v. EPA , 427 U.S.
246 , 256 (1976). The Act, as the majority describes,
established three major regulatory programs to control air
pollution from stationary sources like power plants. See ante , at 2–6. The National Ambient Air Quality Standards
(NAAQS) and Hazardous Air Pollutants (HAP) programs prescribe
standards for specified pollutants, not including carbon dioxide.
Section 111’s New Source Performance Standards program provides an
additional tool for regulating emissions from categories of
stationary sources deemed to contribute significantly to pollution.
As applied to existing (not new) sources, the program mandates—via
Section 111(d)—that EPA set emissions levels for pollutants not
covered by the NAAQS or HAP programs, including carbon dioxide.

															Section 111(d) thus ensures that EPA regulates
existing power plants’ emissions of all pollutants. When the
pollutant at issue falls within the NAAQS or HAP programs, EPA need
do no more. But when the pollutant falls outside those programs,
Section 111(d) requires EPA to set an emissions level for currently
operating power plants (and other stationary sources). That means
no pollutant from such a source can go unregulated: As the Senate
Report explained, Section 111(d) guarantees that “there should be
no gaps in control activities pertaining to stationary source
emissions that pose any significant danger to public health or
welfare.” S. Rep. No. 91–1196, p. 20 (1970). Reflecting that
language, the majority calls Section 111(d) a “gap-filler.” Ante , at 5. It might also be thought of as a backstop or
catch-all provision, protecting against pollutants that the NAAQS
and HAP programs let go by. But the section is not , as the
majority further claims, an “ancillary provision” or a statutory
“backwater.” Ante , at 20, 26. That characterization is a
non-sequitur. That something is a backstop does not make it a
backwater. Even if they are needed only infrequently, see ante , at 6, 20, backstops can perform a critical
function—and this one surely does. Again, Section 111(d) tells EPA
that when a pollutant—like carbon dioxide—is not regulated through
other programs, EPA must undertake a further regulatory effort to
control that substance’s emission from existing stationary sources.
In that way, Section 111(d) operates to ensure that the Act
achieves comprehensive pollution control.

															Section 111 describes the prescribed regulatory
effort in expansive terms. EPA must set for the relevant source
(here, fossil-fuel-fired power plants) and the relevant pollutant
(here, carbon dioxide) an emission level—more particularly,

															“the degree of emission limitation
achievable through the application of the best system of emission
reduction which (taking into account the cost of achieving such
reduction and any nonair quality health and environmental impact
and energy requirements) the [EPA] Administrator determines has
been adequately demonstrated.” §7411(a)(1).

															To take that language apart a bit, the provision
instructs EPA to decide upon the “best system of emission reduction
which . . . has been adequately demonstrated.” The
provision tells EPA, in making that determination, to take account
of both costs and varied “nonair” impacts (on health, the
environment, and the supply of energy). And the provision finally
directs EPA to set the particular emissions limit achievable
through use of the demonstrated “best system.” Taken as a whole,
the section provides regulatory flexibility and discretion. It
imposes, to be sure, meaningful constraints: Take into account
costs and nonair impacts, and make sure the best system has a
proven track record.[ 1 ] But the
core command—go find the best system of emission reduction—gives
broad authority to EPA.

															If that flexibility is not apparent on the
provision’s face, consider some dictionary definitions—supposedly a
staple of this Court’s supposedly textualist method of reading
statutes. A “system” is “a complex unity formed of many often
diverse parts subject to a common plan or serving a common
purpose.” Webster’s Third New International Dictionary 2322 (1971).
Or again: a “system” is “[a]n organized and coordinated method; a
procedure.” American Heritage Dictionary 1768 (5th ed. 2018). The
majority complains that a similar definition—cited to the Solicitor
General’s brief but originally from another dictionary—is just too
darn broad. Ante , at 28; see Brief for United States 31
(quoting Webster’s New International Dictionary 2562 (2d ed.
1959)). “[A]lmost anything” capable of reducing emissions, the
majority says, “could constitute such a ‘system’ ” of emission
reduction. Ante , at 28. But that is rather the point.
Congress used an obviously broad word (though surrounding it with
constraints, see supra , at 7) to give EPA lots of latitude
in deciding how to set emissions limits. And contra the majority, a
broad term is not the same thing as a “vague” one. Ante , at
18, 20, 28. A broad term is comprehensive, extensive, wide-ranging;
a “vague” term is unclear, ambiguous, hazy. (Once again,
dictionaries would tell the tale.) So EPA was quite right in
stating in the Clean Power Plan that the “[p]lain meaning” of the
term “system” in Section 111 refers to “a set of measures that work
together to reduce emissions.” 80 Fed. Reg. 64762. Another of this
Court’s opinions, involving a matter other than the bogeyman of
environmental regulation, might have stopped there.

															For generation shifting fits comfortably within
the conventional meaning of a “system of emission reduction.”
Consider one of the most common mechanisms of generation shifting:
the use of a cap-and-trade scheme. Here is how the majority
describes cap and trade: “Under such a scheme, sources that receive
a reduction in their emissions can sell a credit representing the
value of that reduction to others, who are able to count it toward
their own applicable emissions caps.” Ante , at 8–9. Does
that sound like a “system” to you? It does to me too. And it also
has to this Court. In the past, we have explained that “[t]his type
of ‘cap-and-trade’ system cuts costs while still reducing
pollution to target levels.” EPA v. EME Homer City
Generation, L. P. , 572 U.S.
489 , 503, n. 10 (2014) (emphasis added). So what does the
majority mean when it says that “[a]s a matter of definitional possibilities , generation shifting can be described
as a ‘system’ ”? Ante , at 28 (emphasis added; citation
and some internal quotation marks omitted). Rarely has a statutory
term so clearly applied.

															Other statutory provisions confirm the point.
The Clean Air Act’s acid rain provision, for example, describes a
cap-and-trade program as an “emission allocation and transfer system .” §7651(b) (emphasis added). So a “system,” according
to the statute’s own usage, includes the kind of cap-and-trade
mechanism that the Clean Power Plan relied on. And in a somewhat
different way, the NAAQS provision shows that Section 111
encompasses such a regulatory technique. Under that provision,
cap-and-trade schemes qualify as “control measures, means, or
techniques” that state plans may use to reduce emissions.
§7410(a)(2)(A). That language, of course, does not use the word
“system.” But in specifying that cap and trade is allowable under
the NAAQS program, the provision supports the same conclusion
here—because Section 111 directs EPA to use “a procedure similar to
that provided by [the NAAQS].” §7411(d)(1). The majority discounts
the relevance of both those provisions on the ground that they
contemplate trading systems only “as a means of complying with an already established emissions limit .” Ante ,
at 29 (emphasis in original). That is a distinction, to be sure.
But to begin, it is far less of one than the majority thinks: In
arguing that EPA’s claim of authority here would allow it to take
the emissions limit as low as it wants, the majority ignores the
varied constraints surrounding the “best system” language. See supra , at 7. And still more important for interpretive
purposes, the distinction appears only in the majority’s opinion,
not in any statutory language. That text, to the contrary, says to
EPA: Do as you would do under the NAAQS and Acid Rain programs—go
ahead and use cap and trade.

															There is also a flipside point: Congress
declined to include in Section 111 the restrictions on EPA’s
authority contained in other Clean Air Act provisions. Most
relevant here, quite a number of statutory sections confine EPA’s
emissions- reduction efforts to technological controls—essentially,
equipment or processes that can be put into place at a particular
facility. See ante , at 4 (describing those controls). So,
for example, one provision tells EPA to set standards “reflect[ing]
the greatest degree of emission reduction achievable through the
application of technology.” §7521(a)(3)(A)(i). Others direct the
use of the “best available retrofit technology,” or the “best
available control technology,” or the “maximum achievable control
technology.” §§7491(b)(2)(A), (g)(2), 7475(a)(4), 7479(3),
7412(g)(2). There are still more. See, e.g. , §§7411(h),
7511a(c)(7), 7651f(b)(2). None of those provisions would allow EPA
to set emissions limits based on generation shifting, as the Agency
acknowledges. See Brief for United States 32–33. But nothing like
the language of those provisions is included in Section 111. That
matters under normal rules of statutory interpretation. As Justice
Scalia once wrote for the Court: “We do not lightly assume that
Congress has omitted from its adopted text requirements that it
nonetheless intends to apply, and our reluctance is even greater
when Congress has shown elsewhere in the same statute that it knows
how to make such a requirement manifest.” Jama v. Immigration and Customs Enforcement , 543
U.S. 335 , 341 (2005).

															Statutory history serves only to pile on: It
shows that Congress has specifically declined to restrict EPA to
technology-based controls in its regulation of existing stationary
sources. The key moment came in 1977, when Congress amended Section
111 to distinguish between new sources and existing ones. For new
sources, EPA could select only the “best technological system of continuous emission reduction.” Clean Air Act Amendments,
§109(c)(1)(A), 91Stat. 700 (emphasis added). But for existing
sources, the word “technological” was struck out: EPA could select
the “best system of continuous emission reduction.” Ibid. The House Report emphasized Congress’s deliberate choice: Whereas
the standards set for new sources were to be based on “the best
technological” controls, the “standards adopted for existing
sources” were “to be based on available means of emission control
(not necessarily technological).” H. R. Rep. No. 95–564,
p. 129 (1977). The Report did not further explain the
distinction. But presumably Congress gave EPA more flexibility over
existing plants because imposing technological controls on old
facilities is often not cost- effective.[ 2 ] Thirteen years later, Congress followed up by
deleting from Section 111 the technological limitation applying to
new facilities. See Clean Air Act Amendments of 1990, §403(a),
104Stat. 2631. Once again, then, Congress faced a choice: confine
EPA to technological controls, or not. And replicating its earlier
action for existing sources, Congress chose not.

															The majority breezes past that congressional
choice on the ground that today’s opinion does not resolve whether
EPA can regulate in some non-technological ways; instead, the
opinion says only that the Clean Power Plan goes too far. See ante , at 30–31. That is a puzzling point. As an initial
matter, it recharacterizes what this case has always been about.
The Trump administration repealed the Clean Power Plan for one
central reason: because (in its view) Section 111 confines EPA to
facility-specific, technological measures. See 84 Fed. Reg.
32523–32529. In reviewing that repeal, the court below thus
addressed that limit alone. See American Lung Assn. v. EPA , 985 F.3d 914, 944 (CADC 2021). So add to the oddity of
the Court’s declaring a defunct regulation unlawful, see supra , at 4, the irregularity of its suggesting some kind of
non-technological limit that no one (not EPA, not the parties, not
the court below) has ever considered. More important here, both the
nature and the statutory basis of that limit are left a mystery. If
the majority is not distinguishing between technological controls
and all others, what is it doing—and how far does its opinion
constrain EPA? The majority makes no effort to say. And because
that is so, the majority cannot even attempt to ground its limit in
the statutory language. I’ve just shown that restricting EPA to
technological controls is inconsistent with Section 111, especially
when read in conjunction with other statutory provisions. And the
majority provides no reason to think that its (possibly) different
limit fares any better. Section 111 does not impose any constraints—technological or otherwise—on EPA’s authority to
regulate stationary sources (except for those stated, like cost).
In somehow (and to some extent) saying otherwise, the majority
flouts the statutory text.

															“Congress,” this Court has said, “knows to speak
in plain terms when it wishes to circumscribe, and in capacious
terms when it wishes to enlarge, agency discretion.” Arlington v. FCC , 569 U.S.
290 , 296 (2013). In Section 111, Congress spoke in capacious
terms. It knew that “without regulatory flexibility, changing
circumstances and scientific developments would soon render the
Clean Air Act obsolete.” Massachusetts , 549 U. S., at
532. So the provision enables EPA to base emissions limits for
existing stationary sources on the “best system.” That system may
be technological in nature; it may be whatever else the majority
has in mind; or, most important here, it may be generation
shifting. The statute does not care. And when Congress uses
“expansive language” to authorize agency action, courts generally
may not “impos[e] limits on [the] agency’s discretion.” Little
Sisters of the Poor Saints Peter and Paul Home v. Pennsylvania , 591 U. S. ___, ___ (2020) (slip op., at
16). That constraint on judicial authority—that insistence on
judicial modesty—should resolve this case.

															II

															The majority thinks not, contending that in
“certain extraordinary cases”—of which this is one—courts should
start off with “skepticism” that a broad delegation authorizes
agency action. Ante , at 19. The majority labels that view
the “major questions doctrine,” and claims to find support for it
in our caselaw. Ante , at 19–20, 28. But the relevant
decisions do normal statutory interpretation: In them, the Court
simply insisted that the text of a broad delegation, like any other
statute, should be read in context, and with a modicum of common
sense. Using that ordinary method, the decisions struck down agency
actions (even though they plausibly fit within a delegation’s
terms) for two principal reasons. First, an agency was operating
far outside its traditional lane, so that it had no viable claim of
expertise or experience. And second, the action, if allowed, would
have conflicted with, or even wreaked havoc on, Congress’s broader
design. In short, the assertion of delegated power was a misfit for
both the agency and the statutory scheme. But that is not true
here. The Clean Power Plan falls within EPA’s wheelhouse, and it
fits perfectly—as I’ve just shown—with all the Clean Air Act’s
provisions. That the Plan addresses major issues of public policy
does not upend the analysis. Congress wanted EPA to do just that.
Section 111 entrusts important matters to EPA in the expectation
that the Agency will use that authority to combat pollution—and
that courts will not interfere.

															A

															“[T]he words of a statute,” as the majority
states, “must be read in their context and with a view to their
place in the overall statutory scheme.” FDA v. Brown
& Williamson Tobacco Corp. , 529 U.S.
120 , 133 (2000); see ante , at 16. We do not assess the
meaning of a single word, phrase, or provision in isolation; we
also consider the overall statutory design. And that is just as
true of statutes broadly delegating power to agencies as of any
other kind. In deciding on the scope of such a delegation, courts
must assess how an agency action claimed to fall within the
provision fits with other aspects of a statutory plan.

															So too, a court “must be guided to a degree by
common sense as to the manner in which Congress is likely to
delegate.” Brown & Williamson , 529 U. S., at 133.
Assume that a policy decision, like this one, is a matter of
significant “economic and political magnitude.” Ibid. We
know that Congress delegates such decisions to agencies all the
time—and often via broadly framed provisions like Section 111. See infra , at 29–31. But Congress does so in a sensible way. To
decide whether an agency action goes beyond what Congress wanted,
courts must assess (among other potentially relevant factors) the
nature of the regulation, the nature of the agency, and the
relationship of the two to each other. See, e.g. , Barnhart v. Walton , 535 U.S.
212 , 222 (2002). In particular, we have understood, Congress
does not usually grant agencies the authority to decide significant
issues on which they have no particular expertise. So when there is
a mismatch between the agency’s usual portfolio and a given
assertion of power, courts have reason to question whether Congress
intended a delegation to go so far.

															The majority today goes beyond those sensible
principles. It announces the arrival of the “major questions
doctrine,” which replaces normal text-in-context statutory
interpretation with some tougher-to-satisfy set of rules. Ante , at 16–31. Apparently, there is now a two-step inquiry.
First, a court must decide, by looking at some panoply of factors,
whether agency action presents an “extraordinary case[ ].” Ante , at 17; see ante , at 20–28. If it does, the
agency “must point to clear congressional authorization for the
power it claims,” someplace over and above the normal statutory
basis we require. Ante , at 19 (internal quotation marks
omitted); see ante , at 28–31. The result is statutory
interpretation of an unusual kind. It is not until page 28 of a
31-page opinion that the majority begins to seriously discuss the
meaning of Section 111. And even then, it does not address
straight-up what should be the question: Does the text of that
provision, when read in context and with a common-sense awareness
of how Congress delegates, authorize the agency action here?

															The majority claims it is just following
precedent, but that is not so. The Court has never even used the
term “major questions doctrine” before. And in the relevant cases,
the Court has done statutory construction of a familiar sort. It
has looked to the text of a delegation. It has addressed how an
agency’s view of that text works—or fails to do so—in the context
of a broader statutory scheme. And it has asked, in a
common-sensical (or call it purposive) vein, about what Congress
would have made of the agency’s view—otherwise said, whether
Congress would naturally have delegated authority over some
important question to the agency, given its expertise and
experience. In short, in assessing the scope of a delegation, the
Court has considered—without multiple steps, triggers, or special
presumptions—the fit between the power claimed, the agency claiming
it, and the broader statutory design.

															The key case here is FDA v. Brown
& Williamson . There, the Food and Drug Administration (FDA)
asserted that its power to regulate “drugs” and “devices” extended
to tobacco products. The claim had something to it: FDA has broad
authority over “drugs” and drug-delivery “devices,” and the
definitions of those terms could be read to encompass nicotine and
cigarettes. But the asserted authority “simply [did] not fit” the
overall statutory scheme. 529 U. S., at 143. FDA’s governing
statute required the agency to ensure that regulated products were
“safe” to be marketed—but there was no making tobacco products safe
in the usual sense. Id. , at 133–143. So FDA would have had
to reinterpret what it meant to be “safe,” or else ban tobacco
products altogether. Ibid. Both options, the Court thought,
were preposterous. Until the agency action at issue, tobacco
products hadn’t been spoken of in the same breath as
pharmaceuticals (FDA’s paradigmatic regulated product). And
Congress had created in several statutes a “distinct regulatory
scheme” for tobacco, not involving FDA. Id. , at 155–156. So
all the evidence was that Congress had never meant for FDA to have
any—let alone total—control over the tobacco industry, with its
“unique political history.” Id. , at 159. Again, there was
“simply” a lack of “fit” between the regulation at issue, the
agency in question, and the broader statutory scheme. Id. ,
at 143.

															The majority’s effort to find support in Brown & Williamson for its interpretive approach fails.
See ante , at 19. It may be helpful here to quote the full
sentence that the majority quotes half of. “In extraordinary
cases,” the Court stated, “there may be reason to hesitate before
concluding that Congress has intended such an implicit delegation.”
529 U. S., at 159. For anyone familiar with this Court’s Chevron doctrine, that language will ring a bell. The Court
was saying only—and it was elsewhere explicit on this point—that
there was reason to hesitate before giving FDA’s position Chevron deference. See id. , at 132–133, 159–161. And
what was that reason? The Court went on to explain that it would
not defer to FDA because it read the relevant statutory provisions
as negating the agency’s claimed authority. See id. , at 160
(“[W]e are obliged to defer not to the agency’s expansive
construction of the statute, but to Congress’ consistent judgment
to deny the FDA this power”); id. , at 133 (finding at Chevron ’s first step that “Congress has directly spoken to
the issue here and precluded the FDA’s” asserted power). In
reaching that conclusion, the Court relied (as I’ve just explained)
not on any special “clear authorization” demand, but on normal
principles of statutory interpretation: look at the text, view it
in context, and use what the Court called some “common sense” about
how Congress delegates. Ibid. That is how courts are
to decide, in the majority’s language, whether an agency has
asserted a “highly consequential power beyond what Congress could
reasonably be understood to have granted.” Ante , at 20.

															The Court has applied the same kind of analysis
in subsequent cases—holding in each that an agency exceeded the
scope of a broadly framed delegation when it operated outside the
sphere of its expertise, in a way that warped the statutory text or
structure. In Gonzales v. Oregon , 546 U.S.
243 (2006), we rejected the Attorney General’s assertion of
authority (under a broad “public interest” standard) to rescind
doctors’ registrations for facilitating assisted suicide, even in
States where doing so was legal. See id. , at 243, 248–249,
261–275. We doubted Congress would have delegated such a
“quintessentially medical judgment[ ]” to “an executive
official who lacks medical expertise.” Id. , at 266–267. And
we pointed to statutory provisions in which Congress—in opposition
to the claimed power—had “painstakingly described the Attorney
General’s limited authority” to deregister physicians. Id. ,
at 262.[ 3 ]

															Later, in Utility Air Regulatory Group v. EPA , 573 U.S.
302 (2014), the Court relied on similar reasoning to reject
EPA’s efforts to regulate “millions of small” and previously
unregulated sources of emissions—“including retail stores, offices,
apartment buildings, shopping centers, schools, and churches.” Id. , at 328. Key to that decision was the Court’s view that
reading the delegation so expansively would be “inconsistent with”
the statute’s broader “structure and design.” Id. , at 321.
The Court explained that allowing the agency action to proceed
would necessitate the “rewriting” of other “unambiguous statutory
terms”—indeed, of “precise numerical thresholds.” Id. , at
321, 325–326. (In quoting one cryptic sentence of Utility
Air as supporting its new approach, see ante , at 19, the
majority ignores the nine preceding pages of analysis of the
statute’s text and context, see 573 U. S., at 315–324.)

															And last Term, the Court concluded that the
Centers for Disease Control and Prevention (CDC) lacked the power
to impose a nationwide eviction moratorium. Alabama Assn. of
Realtors v. Department of Health and Human Servs. , 594
U. S. ___, ___–___ (2021) (slip op., at 5–7). The Court held
that other statutory language made it a “stretch” to read the
relied-on delegation as covering the CDC’s action. Id. , at
___ (slip op., at 6). And the Court raised an eyebrow at the
thought of the CDC “intrud[ing]” into “the landlord-tenant
relationship”—a matter outside the CDC’s usual “domain.” Ibid. [ 4 ]

															The eyebrow-raise is indeed a consistent
presence in these cases, responding to something the Court found
anomalous—looked at from Congress’s point of view—in a particular
agency’s exercise of authority. In each case, the Court thought,
the agency had strayed out of its lane, to an area where it had
neither expertise nor experience. The Attorney General making
healthcare policy, the regulator of pharmaceutical concerns
deciding the fate of the tobacco industry, and so on. And in each
case, the proof that the agency had roamed too far afield lay in
the statutory scheme itself. The agency action collided with other
statutory provisions; if the former were allowed, the latter could
not mean what they said or could not work as intended. FDA having
to declare tobacco “safe” to avoid shutting down an industry; or
EPA having literally to change hard numbers contained in the Clean
Air Act. There, according to the Court, the statutory framework was
“not designed to grant” the authority claimed. Utility Air ,
573 U. S., at 324. The agency’s “singular” assertion of power
“would render the statute unrecognizable to the Congress” that
wrote it. Ibid. (internal quotation marks omitted).

															B

															The Court today faces no such singular
assertion of agency power. As I have already explained, nothing in
the Clean Air Act (or, for that matter, any other statute)
conflicts with EPA’s reading of Section 111. Notably, the majority
does not dispute that point. Of course, it views Section 111 (if
for unexplained reasons) as less clear than I do. Compare ante , at 28, with supra , at 7–9. But nowhere does the
majority provide evidence from within the statute itself that the
Clean Power Plan conflicts with or undermines Congress’s design.
That fact alone makes this case different from all the cases
described above. As to the other critical matter in those cases—is
the agency operating outside its sphere of expertise?—the majority
at least tries to say something. It claims EPA has no “comparative
expertise” in “balancing the many vital considerations of national
policy” implicated in regulating electricity sources. Ante ,
at 25–26. But that is wrong.

															Start with what this Court has said before on
the subject, reflecting Congress’s view of the matter. About a
decade ago, we recognized that Congress had “delegated to EPA” in
Section 111 “the decision whether and how to regulate
carbon-dioxide emissions from powerplants.” American Elec.
Power , 564 U. S., at 426. To stress the key word (because
the majority seems to miss it, see ante , at 26–27): not
merely “whether” but also “how.” In making that delegation, we
explained, Congress knew well what it was doing. Regulating power
plant emissions is a complex undertaking. To do it right requires
“informed assessment of competing interests”: “Along with the
environmental benefit potentially achievable, our Nation’s energy
needs and the possibility of economic disruption must weigh in the
balance.” 564 U. S., at 427; see §7411(a)(1) (instructing EPA
to consider “energy requirements,” “cost,” and other factors).
Congress specifically “entrust[ed] such complex balancing to EPA,”
because that “expert agency” has the needed “scientific, economic,
and technological resources” to carry it out. 564 U. S., at
427–428. So the balancing—including of the Nation’s “energy
requirements”—that the majority says EPA has no “comparative
expertise” in? §7411(a)(1); ante , at 25. We explained 11
short years ago, citing Congress, that it was smack in the middle
of EPA’s wheelhouse.

															And we were right. Consider the Clean Power
Plan’s component parts—let’s call them the what, who, and how—to
see the rule’s normalcy. The “what” is the subject matter of the
Plan: carbon dioxide emissions. This Court has already found that
those emissions fall within EPA’s domain. We said then: “[T]here is
nothing counterintuitive to the notion that EPA can curtail the
emission of substances that are putting the global climate out of
kilter.” Massachusetts , 549 U. S., at 531. This is not
the Attorney General regulating medical care, or even the CDC
regulating landlord- tenant relations. It is EPA (that’s the
Environmental Protection Agency, in case the majority forgot)
acting to address the greatest environmental challenge of our time.
So too, there is nothing special about the Plan’s “who”:
fossil-fuel-fired power plants. In Utility Air , we thought
EPA’s regulation of churches and schools highly unusual. See supra , at 18. But fossil-fuel-fired plants? Those plants
pollute—a lot—and so they have long lived under the watchful eye of
EPA. That was true even before EPA began regulating carbon dioxide.
See Train v. Natural Resources Defense Council, Inc. , 421 U.S.
60 , 78 (1975).

															Finally, the “how” of generation shifting
creates no mismatch with EPA’s expertise. As the Plan noted,
generation shifting has a well-established pedigree as a tool for
reducing pollution; even putting aside other federal regulation,
see infra , at 25–26, both state regulators and power plants
themselves have long used it to attain environmental goals. See 80
Fed. Reg. 64664; Brief for Power Company Respondents 47; see also
S. Breyer, Regulation and Its Reform 444, n. 1 (1982) (citing
literature on the subject from the 1970s). The technique is, so to
speak, a tool in the pollution-control toolbox. And that toolbox is
the one EPA uses. So that Agency, more than any other, has the
desired “comparative expertise.” Ante , at 25. The majority
cannot contest that point frontally: It knows that cap and trade
and similar mechanisms are an ordinary part of modern environmental
regulation. Instead, the majority protests that Congress would not
have wanted EPA to “dictat[e],” through generation shifting, the
“mix of energy sources nationwide.” Ante , at 26. But that
statement reflects a misunderstanding of how the electricity market
works. Every regulation of power plants—even the most
conventional, facility- specific controls—“dictat[es]” the national
energy mix to one or another degree. That result follows because
regulations affect costs, and the electrical grid works by taking
up energy from low-cost providers before high-cost ones. Consider
an example: Suppose EPA requires coal-fired plants to use
carbon-capture technology. That action increases those plants’
costs, and automatically (by virtue of the way the grid operates)
reduces their share of the electricity market. So EPA is always
controlling the mix of energy sources. In that sense (though the
term has taken on a more specialized meaning), everything EPA does
is “generation shifting.” The majority’s idea that EPA has no
warrant to direct such a shift just indicates that courts sometimes
do not really get regulation.[ 5 ]

															Why, then, be “skeptic[al]” of EPA’s exercise of
authority? Ante , at 28. When there is no misfit, of the kind
apparent in our precedents, between the regulation, the agency, and
the statutory design? Although the majority offers a flurry of
complaints, they come down in the end to this: The Clean Power Plan
is a big new thing, issued under a minor statutory provision. See ante , at 20, 24, 26 (labeling the Plan “transformative” and
“unprecedented” and calling Section 111(d) an “ancillary”
“backwater”). I have already addressed the back half of that
argument: In fact, there is nothing insignificant about Section
111(d), which was intended to ensure that EPA would limit existing
stationary sources’ emissions of otherwise unregulated pollutants
(however few or many there were). See supra , at 6. And the
front half of the argument doesn’t work either. The Clean Power
Plan was not so big. It was not so new. And to the extent it was
either, that should not matter.

															As to bigness—well, events have proved the
opposite: The Clean Power Plan, we now know, would have had little
or no impact. The Trump administration’s repeal of the Plan created
a kind of controlled experiment: The Plan’s “magnitude”
( ante , at 24) could be measured by seeing how far short the
industry fell of the Plan’s nationwide emissions target. Except
that turned out to be the wrong question, because the industry
didn’t fall short of the Plan’s goal; rather, the industry exceeded
that target, all on its own. See App. 265 (declaration of EPA
official). And it did so mainly through the generation-shifting
techniques that the Plan called for. See ibid. ; Brief for
United States 47. In effect, the Plan predicted market behavior,
rather than altered it (as regulations usually do). Cf. Utility
Air , 573 U. S., at 321–322 (discussing the “calamitous
consequences” of the EPA approach there under review). And that
fact has been understood for some years. At the time of the repeal,
the Trump administration explained that “there [was] likely to be
no difference between a world where the [Clean Power Plan was]
implemented and one where it [was] not.” 84 Fed. Reg.
32561.[ 6 ] It is small wonder,
then, that the power industry overwhelmingly supports EPA in this
case. See Brief for Power Company Respondents 2–3. In the regulated
parties’ view, the rule aimed to achieve what most power companies
also want: substantial reductions in carbon dioxide emissions
accomplished in a cost-effective way while maintaining a reliable
electricity market. See id. , at 26–27, 38, 41–42.

															The majority thus pivots to the massive
consequences generation shifting could produce—but that
claim fares just as poorly. On EPA’s view of its own authority, the
majority worries, some future rule might “forc[e] coal plants to
‘shift’ away virtually all of their generation— i.e. , to
cease making power altogether.” Ante , at 24. But looking at
the text of Section 111(d) might here come in handy. For the
statute imposes, as already shown, a set of
constraints—particularly involving costs and energy needs—that
would preclude so extreme a regulation. See Brief for United States
41–42 (conceding the point); supra , at 7. And if the
majority thinks those constraints do not really constrain, then it
has a much bigger problem. For “traditional” technological
controls, of the kind the majority approves, can have equally
dramatic effects. Ante , at 23. Take, for example, the
“fuel-switching” regulation the majority mentions. Ibid. Such a rule does just what you might think: It requires a plant to
burn a different kind of fuel—say, natural gas instead of coal. So
it too can significantly “restructur[e] the Nation’s overall mix of
electricity generation.” Ante , at 16. Or take an even more
technological-sounding approach: the use of carbon-capture
equipment. Order the installation of that equipment, the Trump
administration concluded, and the “exorbitant” costs “would almost
certainly force the closure” of all affected “coal-fired power
plants.” 84 Fed. Reg. 32548. The point is a simple one: If
generation shifting can go big, so too can technological controls
(assuming, once again, that the statute’s text is ignored). The
problem (if any exists) is not with the channel, but with the
volume.[ 7 ]

															The majority’s claim about the Clean Power
Plan’s novelty—the most fleshed-out part of today’s opinion, see ante , at 20–24—is also exaggerated. As EPA explained when it
issued the Clean Power Plan, an earlier Section 111(d) regulation
had determined that a cap-and-trade program was the “best system of
emission reduction” for mercury. 70 Fed. Reg. 28616–28621 (2005);
see 80 Fed. Reg. 64772. In the majority’s view, that rule was
different because the “actual emission cap” for the contemplated
cap-and-trade scheme was based on the use of a plant-specific
technology—namely, wet scrubbers. Ante , at 21 (internal
quotation marks omitted). But the approval of cap and trade allowed
EPA to make the emissions limits more stringent than it otherwise
could have, because EPA knew that plants unable to cost-effectively
install scrubbers could instead meet the limits through generation
shifting. See 70 Fed. Reg. 28619. EPA could have designed the Clean
Power Plan in the same way—say, by setting emissions limits based
on carbon-capture technology, with the expectation that many plants
would avail themselves of an approved cap-and-trade program
instead. The majority gives no reason to think Section 111(d)
allows that approach but disallows the Clean Power Plan. In both,
generation shifting is operating to increase the strictness of
emissions limits.

															And the mercury rule itself was rooted in
precedent. A decade earlier, EPA had determined that States could
comply with a Section 111(d) regulation for municipal waste
combustors by establishing cap-and-trade programs. See 40 CFR
§§60.30a, 60.33b(d)(2) (1996). And beyond Section 111(d), trading
and other tools of generation shifting become still more common.
For decades, EPA has relied on those pollution-control techniques
in rules covering new internal-combustion engines under Section
111(b), sources of nitrogen oxide under the NAAQS program, and
motor vehicles under Section 202(a). See 73 Fed. Reg. 3595 (2008);
71 Fed. Reg. 39159 (2006); 63 Fed. Reg. 57358–57359 (1998); 48 Fed.
Reg. 33456 (1983); see also Brief for Richard L. Revesz as Amicus Curiae 24–29 (collecting similar rules). No doubt the
majority is right that scrubbers and other “add-on controls” are
“more traditional air pollution control measures.” Ante , at
23. EPA readily acknowledged that fact in developing the Clean
Power Plan. But the idea that the Plan’s reliance on generation
shifting effected some kind of revolution in power-plant pollution
control? No. As I’ve noted before, power plants themselves use that
method. State environmental regulators use that method. And EPA has
used that method, including under the statutory provision invoked
here.

															In any event, newness might be perfectly
legitimate—even required—from Congress’s point of view. I do not
dispute that an agency’s longstanding practice may inform a court’s
interpretation of a statute delegating the agency power. See ante , at 20–21. But it is equally true, as Brown &
Williamson recognized, that agency practices are “not carved in
stone.” 529 U. S., at 156–157 (internal quotation marks
omitted). Congress makes broad delegations in part so that agencies
can “adapt their rules and policies to the demands of changing
circumstances.” Id. , at 157. To keep faith with that
congressional choice, courts must give agencies “ample latitude” to
revisit, rethink, and revise their regulatory approaches. Ibid. So it is here. Section 111(d) was written, as I’ve
shown, to give EPA plenty of leeway. See supra , at 6–8. The
enacting Congress told EPA to pick the “best system of emission
reduction” (taking into account various factors). In selecting
those words, Congress understood—it had to—that the “best system”
would change over time. Congress wanted and instructed EPA to keep
up. To ensure the statute’s continued effectiveness, the “best
system” should evolve as circumstances evolved—in a way Congress
knew it couldn’t then know. See Massachusetts , 549
U. S., at 532. EPA followed those statutory directions to the
letter when it issued the Clean Power Plan. It selected a system
(as the regulated parties agree) that achieved greater emissions
reductions at lower cost than any technological alternative could
have, while maintaining a reliable electricity market. Even if that
system was novel, it was in EPA’s view better—actually, “best.” So
it was the system that accorded with the enacting Congress’s
choice.

															And contra the majority, it is that Congress’s
choice which counts, not any later one’s. The majority says it
“cannot ignore” that Congress in recent years has “considered and
rejected” cap-and-trade schemes. Ante , at 27–28. But under
normal principles of statutory construction, the majority should ignore that fact (just as I should ignore that
Congress failed to enact bills barring EPA from implementing the
Clean Power Plan). As we have explained time and again, failed
legislation “offers a particularly dangerous basis on which to rest
an interpretation of an existing law a different and earlier
Congress” adopted. Bostock v. Clayton County , 590
U. S. ___, ___ (2020) (slip op., at 20) (internal quotation
marks omitted); see Sullivan v. Finkelstein , 496 U.S.
617 , 632 (1990) (Scalia, J., concurring in part) (“Arguments
based on subsequent legislative history” should “not be taken
seriously, not even in a footnote”). Return to Brown &
Williamson , which all agree is the key case in this sphere. It
disclaimed any reliance on “Congress’ failure” to grant FDA
jurisdiction over tobacco. 529 U. S., at 155. Instead, the
Court focused on the statutes Congress “ ha[d] enacted,”
which created “a distinct regulatory scheme” for tobacco,
incompatible with FDA’s. Ibid. (emphasis added). Here, as
I’ve shown and the majority effectively concedes, there is nothing
equivalent. See supra , at 9–12. Search high and low, nothing
in current law conflicts with, or otherwise casts doubt on, the
Clean Power Plan. That leaves the Court in much the same place it
was when deciding Massachusetts v. EPA . Said the
Court then: “That subsequent Congresses have eschewed enacting
binding emissions limitations to combat global warming tells us
nothing about what Congress meant” when it enacted the Clean Air
Act. 549 U. S., at 529–530. And so the Court recognized EPA’s
authority to regulate carbon dioxide. But that Court was not this
Court; and this Court deprives EPA of the authority Congress gave
it in Section 111(d) to respond to the same environmental
danger.

															III

															Some years ago, I remarked that “[w]e’re all
textualists now.” Harvard Law School, The Antonin Scalia Lecture
Series: A Dialogue with Justice Elena Kagan on the Reading of
Statutes (Nov. 25, 2015). It seems I was wrong. The current Court
is textualist only when being so suits it. When that method would
frustrate broader goals, special canons like the “major questions
doctrine” magically appear as get-out-of-text-free cards.[ 8 ] Today, one of those broader goals
makes itself clear: Prevent agencies from doing important work,
even though that is what Congress directed. That
anti-administrative-state stance shows up in the majority opinion,
and it suffuses the concurrence. See ante , at 19, 25–26; e.g. , ante , at 3–6 (Gorsuch, J., concurring).

															The kind of agency delegations at issue here go
all the way back to this Nation’s founding. “[T]he founding era,”
scholars have shown, “wasn’t concerned about delegation.” E. Posner
& A. Vermeule, Interring the Nondelegation Doctrine, 69
U. Chi. L. Rev. 1721, 1734 (2002) (Posner &
Vermeule). The records of the Constitutional Convention, the
ratification debates, the Federalist—none of them suggests any
significant limit on Congress’s capacity to delegate policymaking
authority to the Executive Branch. And neither does any early
practice. The very first Congress gave sweeping authority to the
Executive Branch to resolve some of the day’s most pressing
problems, including questions of “territorial administration,”
“Indian affairs,” “foreign and domestic debt,” “military service,”
and “the federal courts.” J. Mortenson & N. Bagley, Delegation
at the Founding, 121 Colum. L. Rev. 277, 349 (2021)
(Mortenson & Bagley). That Congress, to use a few examples,
gave the Executive power to devise a licensing scheme for trading
with Indians; to craft appropriate laws for the Territories; and to
decide how to pay down the (potentially ruinous) national debt. See id. , at 334–338, 340–342, 344–345; C. Chabot, The Lost
History of Delegation at the Founding, 56 Ga. L. Rev. 81,
113–134 (2021) (Chabot). Barely anyone objected on delegation
grounds. See Mortenson & Bagley 281–282, 332, 339; Chabot
117–119; Posner & Vermeule 1733–1736.

															It is not surprising that Congress has always
delegated, and continues to do so—including on important policy
issues. As this Court has recognized, it is often “unreasonable and
impracticable” for Congress to do anything else. American Power
& Light Co. v. SEC , 329 U.S.
90 , 105 (1946). In all times, but ever more in “our
increasingly complex society,” the Legislature “simply cannot do
its job absent an ability to delegate power under broad general
directives.” Mistretta v. United States , 488 U.S.
361 , 372 (1989). Consider just two reasons why.

															First, Members of Congress often don’t know
enough—and know they don’t know enough—to regulate sensibly on an
issue. Of course, Members can and do provide overall direction. But
then they rely, as all of us rely in our daily lives, on people
with greater expertise and experience. Those people are found in
agencies. Congress looks to them to make specific judgments about
how to achieve its more general objectives. And it does so
especially, though by no means exclusively, when an issue has a
scientific or technical dimension. Why wouldn’t Congress
instruct EPA to select “the best system of emission reduction,”
rather than try to choose that system itself? Congress knows that
systems of emission reduction lie not in its own but in EPA’s
“unique expertise.” Martin v. Occupational Safety and
Health Review Comm’n , 499 U.S.
144 , 151 (1991).

															Second and relatedly, Members of Congress often
can’t know enough—and again, know they can’t—to keep regulatory
schemes working across time. Congress usually can’t predict the
future—can’t anticipate changing circumstances and the way they
will affect varied regulatory techniques. Nor can Congress
(realistically) keep track of and respond to fast-flowing
developments as they occur. Once again, that is most obviously true
when it comes to scientific and technical matters. The “best system
of emission reduction” is not today what it was yesterday, and will
surely be something different tomorrow. So for this reason too, a
rational Congress delegates. It enables an agency to adapt old
regulatory approaches to new times, to ensure that a statutory
program remains effective. See, e.g. , National Federation
of Independent Business v. OSHA , 595 U. S. ___, ___
(2022) (Breyer, Sotomayor, and Kagan, JJ., dissenting) (slip op.,
at 9) (observing that a statute’s broad language was meant to
ensure that an agency had “the tools needed to confront emerging
dangers”).

															Over time, the administrative delegations
Congress has made have helped to build a modern Nation. Congress
wanted fewer workers killed in industrial accidents. It wanted to
prevent plane crashes, and reduce the deadliness of car wrecks. It
wanted to ensure that consumer products didn’t catch fire. It
wanted to stop the routine adulteration of food and improve the
safety and efficacy of medications. And it wanted cleaner air and
water. If an American could go back in time, she might be
astonished by how much progress has occurred in all those areas. It
didn’t happen through legislation alone. It happened because
Congress gave broad-ranging powers to administrative agencies, and
those agencies then filled in—rule by rule by rule—Congress’s
policy outlines.

															This Court has historically known enough not to
get in the way. Maybe the best explanation of why comes from
Justice Scalia. See Mistretta , 488 U. S., at 415–416
(dissenting opinion). The context was somewhat different. He was
responding to an argument that Congress could not constitutionally
delegate broad policymaking authority; here, the Court reads a
delegation with unwarranted skepticism, and thereby artificially
constrains its scope. But Justice Scalia’s reasoning remains on
point. He started with the inevitability of delegations: “[S]ome
judgments involving policy considerations,” he stated, “must be
left to [administrative] officers.” Id. , at 415. Then he
explained why courts should not try to seriously police those
delegations, barring—or, I’ll add, narrowing—some on the ground
that they went too far. The scope of delegations, he said,

															“must be fixed according to common sense
and the inherent necessities of the governmental co-ordination.
Since Congress is no less endowed with common sense than we are,
and better equipped to inform itself of the necessities of
government; and since the factors bearing upon those necessities
are both multifarious and (in the nonpartisan sense) highly
political . . . it is small wonder that we have almost
never felt qualified to second-guess Congress regarding the
permissible degree of policy judgment that can be left to those
executing or applying the law.” Id. , at 416 (internal
quotation marks omitted).

															In short, when it comes to delegations, there
are good reasons for Congress (within extremely broad limits) to
get to call the shots. Congress knows about how government works in
ways courts don’t. More specifically, Congress knows what mix of
legislative and administrative action conduces to good policy.
Courts should be modest.

															Today, the Court is not. Section 111, most
naturally read, authorizes EPA to develop the Clean Power Plan—in
other words, to decide that generation shifting is the “best system
of emission reduction” for power plants churning out carbon
dioxide. Evaluating systems of emission reduction is what EPA does.
And nothing in the rest of the Clean Air Act, or any other statute,
suggests that Congress did not mean for the delegation it wrote to
go as far as the text says. In rewriting that text, the Court
substitutes its own ideas about delegations for Congress’s. And
that means the Court substitutes its own ideas about policymaking
for Congress’s. The Court will not allow the Clean Air Act to work
as Congress instructed. The Court, rather than Congress, will
decide how much regulation is too much.

															The subject matter of the regulation here makes
the Court’s intervention all the more troubling. Whatever else this
Court may know about, it does not have a clue about how to address
climate change. And let’s say the obvious: The stakes here are
high. Yet the Court today prevents congressionally authorized
agency action to curb power plants’ carbon dioxide emissions. The
Court appoints itself—instead of Congress or the expert agency—the
decision-maker on climate policy. I cannot think of many things
more frightening. Respectfully, I dissent. Notes 1 Those constraints have
had real effect: They have led EPA in prior rulemakings to exclude
a number of pollution-control measures from the “best system of
emission reduction.” See Brief for United States 49 (collecting
citations). 2 The majority offers a
theory for why Congress insisted on a technological system for new
sources: It was, the majority says, to prevent EPA’s use of a
particular kind of technological system (involving fuel switching)
to achieve emissions reductions. See ante , at 22, n. 2,
23. To begin with: I don’t see how requiring EPA to select among
technological systems precludes it from picking what the majority
agrees is one such measure. See ante , at 4, 22, n. 2,
22–23. But more important, I can’t see why the majority’s
explanation matters. Let’s assume the majority is right about
Congress’s motive. The key point remains the same: Whatever that
motive, Congress’s instruction to use technological systems applied
only to new sources, and not to existing ones. As to the latter,
Congress allowed EPA more latitude: The Agency could use
technological or non-technological methods, as it preferred.
That distinction is what creates interpretive difficulties for the
majority—again, no matter why it arose. 3 Similarly, in King v. Burwell , 576 U.S. 473 (2015), we relied on Brown &
Williamson in declining to defer to the Internal Revenue
Service’s construction of the Affordable Care Act. We thought it
highly “unlikely that Congress would have delegated” an important
decision about healthcare pricing to an agency with “no expertise
in crafting health insurance policy.” 576 U. S., at
486. 4 Not every Justice, of
course, agreed with the Court’s conclusions in the above-discussed
cases; to be frank, I dissented in a couple. But what matters here
is the analysis those decisions undertook—and how, as I’ll
describe, it supports EPA’s Clean Power Plan. 5 The majority’s only
response to the argument above similarly reveals a misperception as
to the practical impact of different regulatory techniques.
According to the majority, there is an “obvious difference” between
changing the energy mix by conventional technological regulation
and doing so by measures like cap and trade. Ante , at 27,
n. 4. But in fact there is not. As I’ll detail later,
generation shifting can effect a significant—or instead an
insignificant—change in the energy mix; and the same is true of
technological regulations. See infra , at 24–25. It all
depends on the specifics: There is no necessary connection (in
either direction) between the kind of regulation and the
magnitude of its effect. For example, a rule requiring the use of
carbon-capture technology would have shifted far more electricity
production from coal-fired plants than the Clean Power Plan would
have. See ibid. In suggesting that cap-and-trade programs
are somehow more suspect, the majority merely serves to
disadvantage what is often the smartest kind of regulation:
market-based programs that achieve the biggest bang for the buck.
That is why so many power companies are on EPA’s side in this
litigation. 6 Even when the Clean Power
Plan was first issued, its projected impact was far less than what
the majority implies. The majority states, for example, that the
rule would have “reduce[d] GDP by at least a trillion 2009 dollars
by 2040.” Ante , at 10. That sounds like a lot, but it is in
fact “equivalent to changes of a few tenths of 1 percent from
baseline.” Dept. of Energy, Analysis of the Impacts of the Clean
Power Plan 63–64 (2015). And the “billions of dollars in compliance
costs” the majority highlights were vastly outweighed by the Plan’s
projected benefits. Ante , at 10; see 80 Fed. Reg. 64679
(anticipating $5–$8 billion in costs and $32–$54 billion in
benefits by 2030); see also EPA, Regulatory Impact Analysis for the
Clean Power Plan Final Rule 6–35 (2015) (estimating that by 2030
jobs gained from the Plan would be some two or three times greater
than jobs lost). 7 The majority dismisses
these hypotheticals as fantastical, protesting that “EPA has never
ordered anything remotely like [them], and we doubt it could.” Ante , at 24, n. 3. But that’s just the point. EPA
hasn’t forced the elimination of coal plants—whether through
technological controls or generation shifting— because the
statutory constraints prevent it from doing so. The majority offers
no reason to think that those constraints suffice for the measures
it approves (fuel switching and carbon capture) but not for the
measure it rejects (generation shifting). Either the constraints
are enough or they are not. The majority cannot have it both
ways. 8 The majority opinion at
least addresses the statute’s text, though overstating its
ambiguity and approaching the action taken under it with
unwarranted “skepticism.” Ante , at 28; see ante , at
28–31. The concurrence, by contrast, concludes that the Clean Air
Act does not clearly enough authorize EPA’s Plan without ever
citing the statutory text. See ante , at 13–16. Nowhere will
you find the concurrence ask: What does the phrase “best system of
emission reduction” mean? §7411(a)(1). So much for “begin[ning], as
we must, with a careful examination of the statutory text.” Henson v. Santander Consumer USA Inc. , 582 U.S. 79,
___ (2017) (slip op., at 3).