Stem cell laws and policy in the United States
In May 2005, the House of Representatives voted 238-194 to loosen the limitations on federally funded embryonic stem-cell research — by allowing government-funded research on surplus frozen embryos from in vitro fertilization clinics to be used for stem cell research with the permission of donors — despite Bush's promise to veto if passed.  On July 29, 2005, Senate Majority Leader William H. Frist (R-TN), announced that he too favored loosening restrictions on federal funding of embryonic stem cell research. On July 18, 2006, the Senate passed three different bills concerning stem cell research. The Senate passed the first bill, 63-37, which would have made it legal for the Federal government to spend Federal money on embryonic stem cell research that uses embryos left over from "in vitro" fertilization procedures. On July 19, 2006 President Bush vetoed this bill. The second bill makes it illegal to create, grow, and abort fetuses for research purposes. The third bill would encourage research that would isolate pluripotent, i.e., embryonic-like, stem cells without the destruction of human embryos.
Political positions of John McCain
McCain was a member of The Republican Main Street Partnership and supported embryonic stem cell research. McCain had earlier opposed embryonic stem cell research and credits former First Lady Nancy Reagan, a prominent Republican supporter of such research, with changing his mind in 2001. He states that he believes that stem cell research, and indeed embryonic stem cell research, will continue whether or not the U.S. sanctions it, and so it would be the wisest course of action to support it to the extent that the United States will be able to regulate and monitor the use. In July 2008 he said "At the moment I support stem cell research [because of] the potential it has for curing some of the most terrible diseases that afflict mankind."