Lawmakers are expected to support a repeal of President Bush's funding limits on embryonic stem cell research when the Senate takes up a series of bills beginning Monday.
Backers of the research are expressing cautious confidence they'll succeed in passing the bill. But they also expect Bush to veto the measure; it would be the president's first veto.
"The conventional wisdom is we have enough votes," Sen. Arlen Specter, (R-Pa.), a sponsor of the bill, tells WebMD.
Embryonic stem cells that are "pluripotent" have the ability to become any type of cell in the body, such as a brain cell or muscle cell. Scientists say that gives them great promise in treating a wide range of health problems, including diabetes, Alzheimer's disease, or spinal cord injuries.
Some opponents of abortion are opposed to stem cell research because it requires the destruction of embryos for the harvesting of stem cells.
Federal funding for the research was strictly limited in August 2001 when
President Bush confined government support to roughly 70 stem cell lines already created at the time. At the time, Mr. Bush said the decision would allow research to progress without spending taxpayer money on studies that destroy embryos.
Scientists have since complained that most of the cell lines allowed under the policy are useless for research because of contamination and other issues.
Several states, including California, Maryland, and Massachusetts, have passed legislation funding stem cell research.
The Senate bill, which passed the House last May with wide bipartisan support, would put the National Institutes of Health in charge of nationally funded research using excess embryos left over from fertilization treatments as a source of stem cells. Supporters say research can derive benefits from the embryos, which otherwise are destroyed when no longer needed.
"I think the White House is doing everything they can to stop it," said Sen. Orrin Hatch (R-Utah), an opponent of abortion who strongly supports the research. "A vote against it is to be on the wrong side of history," he says.
"I'm pretty confident," says Sen. Dianne Feinstein, (D-Calif.), a co-sponsor of the bill.
Sen. Tom Coburn, (R-Okla.), a doctor who is an opponent of the research, accused supporters of promoting myths about the promise of embryonic stem cells to treat diseases.
"I'm going to be there to answer it with science every time somebody says something that's untrue," he says.
Even if supporters muster the 60 votes needed to pass the bill Tuesday night, lawmakers on both sides say they expect the president will veto it.
"We expect a veto as early as Wednesday afternoon," a senior Democratic aide says.
Still, Mr. Bush could pair his veto with support for two other bills also scheduled for Senate debate Monday and Tuesday. One would ban the implantation of an embryo in the womb of a woman or animal for research purposes.
Another would open federal funding for experimental methods of extracting stem cells without damaging embryos.
Researchers testified on Capitol Hill earlier this month that alternative extraction methods remain theoretical, but that the techniques are worth pursuing.
The bill could offer lawmakers -- and the president -- a way to support some stem cell research popular with voters without violating their vows not to support studies that harm embryos, says Rep. Phil Gingrey, (R-Ga.), who supports the alternative measure but opposes the embryonic stem cell research bill.
Gingrey tells WebMD that he and other conservatives are "counting on" President Bush to veto the expansion of research that destroys embryos, even if the decision causes political trouble for Republicans in this year's elections.
"I think it definitely could be a political liability if we didn't have the other bill as an alternative," says Gingrey, who is a doctor.
The Senate is expected to vote on all three bills on Tuesday evening.
SOURCES:: Sen. Arlen Specter (R-Pa.). Sen. Orrin Hatch (R-Utah). Sen. Dianne Feinstein (D-Calif.). Sen. Tom Coburn, (R-Okla.). Rep. Phil Gingrey, (R-Ga.).
By Todd Zwillich
Reviewed by Louise Chang, M.D.
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