In the heated debate among conservatives over whether Mitt Romney deserves their vote, the focus has been largely on whether his big swings to the right on social issues are sincere.
But on the charged issue of stem cell research, he's facing conservative criticism of a different shade: that he hasn't swung far enough.
Unlike many on the right, Romney supports research on excess embryos created during fertility treatments. Because couples are making embryos to have a baby, he reasons, it is ethical to use the leftovers for research when they would otherwise just be discarded.
Romney's position, however, is at odds with the views of many conservative anti abortion activists, who believe that any work on stem cells derived from human embryos is wrong, because it destroys the embryos in the process. Some say Romney's views make him unacceptable to many voters and will complicate his attempt to win the 2008 GOP nomination by appealing to the party's conservative flank.
Romney's views on stem cell research, which have drawn little public scrutiny amid the static over his shifts on abortion and gay rights, are sure to attract more attention with Congress poised to pass a bill expanding federal support for human embryonic stem cell research, the latest flashpoint in a long-running debate about the sanctity of life and when it begins.
"It's a no-no for some people," Nick Lantinga, a Republican activist in heavily conservative northwest Iowa, said of Romney's support of using excess embryos.
Research on stem cells extracted from human embryos is considered promising by scientists because such cells have the capacity to develop into any cell in the body, and thus could hold insights and, possibly, cures for diseases such as juvenile diabetes.
The embryos come from two sources: They are either created in a lab by implanting human DNA into a donated egg, or the embryos are left over from fertility treatments. In both cases, the embryos are destroyed.
Thus many conservatives object to both scenarios, believing the far-off prospect of medical advances doesn't justify the destruction of human life. Citing such concerns, President Bush announced on Aug. 9, 2001, that he was banning federal funding for research on human embryonic stem cell lines created after that date.
Congress sought to lift the ban last year by passing the CastleDeGette bill. The measure seeks to promote, under certain conditions, research on embryos left over from fertility treatments by sanctioning federal funding for it. It would not authorize federal funding for research that involves cloning.
Bush, using his first presidential veto, rejected the bill.
But the issue is pressing again -- the House passed an identical measure last month and the Senate is expected to follow suit. With Congress still apparently lacking the votes to override a Bush veto, the views of the next president are crucial.
Romney, in an illustration of his delicate maneuvering on the issue, supports the principle at the heart of the bill -- that it's ethical to use excess embryos for research -- but opposes the bill itself, in part because he objects to any expansion of taxpayer-funded human embryonic stem cell research.
Romney aide Peter Flaherty explained in an e-mail statement that Romney does not believe the public should pay for research that is "ethically troublesome."
"Governor Romney believes that because of its inherent ethical issues this research should not be funded by the taxpayers," Flaherty said, adding that Romney supports government funding of research into alternative methods of extracting stem cells.
Romney's opposition to expanded government funding was touted last month by a South Carolina senator, Jim DeMint , who, in a letter to Republicans announcing his endorsement of Romney, assured conservatives Romney would keep "the ban on federal funding of research that involves the killing of human embryos."
Romney's views on stem cell research have evolved over the past five years. When he ran for governor in 2002, he endorsed embryonic stem cell research in broad terms, saying at one campaign stop that he would lobby Bush to embrace it.
But in February 2005, as the state Legislature was considering a bill to promote embryonic stem cell research, Romney, after consulting with specialists on both sides of the issue, tried to forge a middle ground: He would fight efforts to clone human embryos for research, he said, but believed it was ethical to experiment on embryos left over from fertility treatments.
Romney continues to hold that position, but he also now expresses opposition to expanding federal funding for research on excess embryos.
Richard Land, president of the Southern Baptist Convention's Ethics & Religious Liberty Commission, said that while Romney's support for research on leftover embryos will be troubling to some voters, his opposition to the bill seeking expanded federal funding will help him.
"I think he needs to say at every point that he supports the president's veto," Land said.
But just because Romney agrees with conservatives on maintaining the ban on federal funding, his support in general for using leftover embryos in research will not sit well with Christian conservatives who help decide GOP primaries, some say.
"Any position that throws open the door to using the frozen embryos is going to be a position that Catholics and many other Christians will not be able to stand behind in any way," said the Rev. Tadeusz Pacholczyk , an ethicist with the National Catholic
Tom McClusky, vice president for government affairs for the influential Family Research Council, noted that Romney, after his education on stem cell research as governor led him to abandon his past support for abortion rights, now describes himself as "firmly pro-life." But the organization is concerned that Romney's position on stem cell research is not a pure "pro-life" position.
"I would think it's going to be a problem," he said.
And Joe Mack, public policy director for the South Carolina Baptist Convention, said it was not valid to assume that leftover embryos are going to be destroyed. Mack believes embryos should be preserved for possible future use. Candidates' positions on stem cell research, he added, would be critical to many religious conservatives as they decide whom to back for president.
Supporters of using leftover embryos counter that the more moral position is to try to put them to some good.
"If they can be used to help people with medical challenges, better use them for life than to waste them," said US Representative Ralph Regula, a Republican from Ohio who is supporting Romney.
In his campaign , Romney hasn't entirely avoided his support for embryonic stem cell research, mentioning it briefly, for example, in an address to a conference on conservatism put on by National Review magazine in Washington two weeks ago. But he doesn't dwell on it, either, instead tending to highlight his opposition to creating cloned embryos.
A May 2005 interview on Fox News illustrates the difficult path he's treading. Chris Wallace had Romney on a show with Boomer Esiason, a former NFL quarterback and proponent of embryonic stem cell research. After hearing Esiason make his case, Wallace turned to Romney.
"Let's talk first of all about the fact that you support the idea of using these embryos that are left over in fertility clinics and that would otherwise simply be thrown away," Wallace said.
Romney didn't directly address the point, saying that he draws the ethical line "in a very similar place" to that of Bush.
Wallace tried again: "But if I may ask you, governor, specifically, you don't see, as I understand it, the use of these leftover embryos in fertility clinics as destroying life?"
"That's right," Romney responded, later adding that he feels "very much like Boomer Esiason does."
A few conservatives have questioned whether Romney and his supporters are trying to muddy his views.
"Mitt Romney's position on embryonic stem cell research is not pro-life, and no one should say that it is," the Republican National Coalition for Life, a group founded by conservative icon Phyllis Schlafly, said in a weekly e-mail.
But Land said Romney's position on stem cells should not be judged in a vacuum. How big a hurdle it will be for him, Land said, depends on who his main rivals are a year from now.
"If his main competition turns out to be someone who is even more pro-life, then this is going to be really problematic," Land said. "If his main competition is [former New York mayor] Rudy Giuliani, it won't matter."