U.S. President George W. Bush cast his first veto on Wednesday to block legislation to expand embryonic stem cell research, putting him at odds with top scientists, most Americans and some fellow Republicans.
"It crosses a moral boundary that our decent society needs to respect, so I vetoed it," Bush said of the research that involves tiny human embryos.
The U.S. House failed to muster the two-thirds vote necessary to override the veto, Bush's first in more than five years in the White House. The vote was 235-193.
The issue has become ethically and politically volatile because extracting the cells entails destruction of an embryo.
Bush believes that is destroying a life. His opponents say the research, which would be done only on excess embryos from fertility treatments that would otherwise be destroyed, is potentially life-saving.
The debate has become an issue in several of this November's Senate races and it may factor in the 2008 presidential contest.
The veto fulfills a Bush promise made to socially conservative supporters whose votes his Republican Party will need in November to help keep control of Congress.
But Democrats, citing opinion polls showing that most Americans support the research that could lead to new treatments for conditions ranging from diabetes to paralysis, said that Bush's stance may alienate centrist voters.
Iowa Democrat Sen. Tom Harkin called the veto a "shameful display of cruelty, hypocrisy, and ignorance" that crushed the hopes of millions of suffering people. He vowed to reintroduce the legislation next year.
Even conservative Republicans who generally oppose abortion are split. Some prominent anti-abortion Republicans including Senate Majority Leader Bill Frist of Tennessee and Sen. Orrin Hatch of Utah championed the legislation but most of Bush's fellow conservatives shared the president's view.
"The notion that embryonic stem cell research relies on "spare embryos" that have no value beyond their possibilities for medical research is tragically and deceptively wrong," House Majority Leader John Boehner of Ohio said as the House voted to back the president.
In 2001, Bush allowed federally funded research on 78 stem-cell lines already in existence, most of which proved inadequate for research.
The bill he vetoed would have expanded the number of stem cell lines available for federally funded science. The destruction of the embryos themselves, however, would have to be done with private funds, not taxpayer dollars, said Colorado Democrat Diana DeGette, a co-author of the bill.
CROSSING 'MORAL LINE'
Bush advocated searching for stem-cell techniques that advanced science in an "ethical and morally responsible way."
"I made it clear to the Congress that I will not allow our nation to cross this moral line," he told a White House audience including women who had children after adopting and gestating "spare" embryos from fertility clinics. "I felt like crossing this line would be a mistake and once crossed we would find it almost impossible to turn back."
Anti-abortion groups have praised Bush's stance, and his allies said the proponents of embryonic stem cell research exaggerated its potential. During the House debate on Tuesday, New Jersey Republican Chris Smith said he had seldom seen so much "hyperbole and misinformation."
But leading researchers and patient advocacy groups, such as the Christopher Reeve Foundation and the Michael J. Fox Foundation for Parkinson's Research, had strongly pushed Bush to sign the bill. Former first lady Nancy Reagan, widow of former President Ronald Reagan who died of Alzheimer's disease, also lobbied for it passionately.
Britain has passed laws encouraging embryonic stem-cell research. Canada and New Zealand have passed legislation to fund it.
Bush is the first president to complete four years in office without a veto since John Quincy Adams in the 1820s. He had threatened vetoes before but refrained after reaching compromises with the Republican-controlled Congress.
Bush also signed into law a noncontroversial bill that outlaws "fetus farming" or creating a pregnancy for the purpose of harvesting the fetus for its cells or tissues.
He had hoped to sign a second bill that would encourage alternative stem cell research, but House Democrats blocked it on Tuesday, saying its only purpose was to provide political cover for conservatives. (Additional reporting by Patricia Wilson)