WASHINGTON The Democratic-led U.S. Senate voted on Wednesday to lift a key restriction by President George W. Bush on the federal funding of embryonic stem cell research.
But Congress is not expected to muster the two-thirds majority votes to override a promised Bush veto, leaving the emotionally charged issue to resurface in next year's presidential and congressional races.
The Senate passed legislation to eliminate a nearly 6-year-old Bush restriction, 63-34, with 17 Republicans and two independents joining 44 Democrats in voting aye.
Bush vetoed a similar bill last year. It would expand federal funding of stem cell research, which is now limited by the president to batches available as of August 2001. Democrats vowed to lift this restriction in winning control of Congress in November from Bush's fellow Republicans.
Advocates and a majority of Americans back embryonic stem cell research. Proponents say it offers major hope for cures for such ailments as Parkinson's disease, diabetes and spinal cord injuries. But the testing requires destruction of days-old embryos that is condemned by many anti-abortion advocates.
Sen. Tom Harkin, an Iowa Democrat and chief sponsor of the bill, urged Bush "to reconsider his threat to veto it."
"There are some 400,000 leftover, unwanted embryos in fertility clinics across America," Harkin said. "All we are saying is, instead of throwing those leftover embryos away, let's allow couples to donate a few of them, if they wish, to create stem cell lines that could cure diseases and save lives."
Bush reiterated his vow to veto the bill, but said he would sign into law an alternative measure that the Senate passed 70-28 shortly afterward with mostly Republican support.
This measure would encourage research on certain forms of stem cells but not beyond Bush's 2001 restrictions. Critics called the measure a sham that would merely let lawmakers say they voted for stem cell research.
But proponents said it would provide a needed step forward by allowing research on some embryos that can no longer develop into fetuses.
"I strongly support this bill, and I encourage the Congress to pass it and send it to me for my signature, so stem cell science can progress, without ethical and cultural conflict," Bush said.
Shortly after taking office in 2001, Bush issued an executive order that permitted for the first time federal funding of human embryonic stem cell research. But he limited it to batches available as of that August.
The bill first passed by the Senate on Wednesday would lift this restriction, but keep in place one that prohibits use of federal funds to create embryos via cloning or other technology.
To override a veto, a two-thirds majority vote would be needed in the Senate and House of Representatives. In January, the House passed a similar bill, but far short of a two-thirds margin.
Yet Republican and Democrat backers predicted such legislation will eventually become law.
"He (Bush) is not going to be president forever," said Sen. Russ Feingold, a Wisconsin Democrat.
Stem cells are a kind of master cell for the body, capable of growing into various tissue and cell types. Scientists hope to use the cells from embryos to repair damaged tissue.
(Additional reporting by Maggie Fox, Richard Cowan and Toby Zakaria)