WASHINGTON -- The debate over stem cells is shifting to the halls of Congress, but the action is moving to the nation's laboratories as scientists begin the painstaking work of translating promise into actual treatments.
President Bush's decision to allow limited federal funding for the research offered both comfort and angst to advocates on both sides of the debate. And it complicated the politics all around. Bush may have satisfied just enough people just enough to stave off congressional action.
"The president probably bought himself some time," said Thomas Mann, an expert on Congress at the Brookings Institution. "Pressure will build again, but it will take some time."
At issue is research involving days-old human embryos, each one smaller than the period at the end of this sentence, left over from fertility treatments. Inside sit stem cells that can develop into any type of tissue.
Scientists say these cells could help cure many diseases, but in order to get them out, the embryo must be destroyed. For some who believe life begins at conception, this amounts to taking one life to try and save another.
Trying to thread an ethical needle, Bush said Thursday that he would allow federal funding for research on stem cell lines, but only those that have already been created. Each embryo can yield one stem cell line, which can continue replicating indefinitely.
At the National Institutes of Health on Friday, researchers were beginning to catalogue the existing stem cell lines, which officials now estimate at 60 worldwide. Around the country, scientists were beginning to hone their ideas for grant applications, which were expected to be submitted and awarded by early next year.
Dr. Harold Varmus, who led the NIH under President Clinton, predicted that hundreds of researchers would get into the field, even under limited federal funding. Ultimately, he predicted that the federal government would spend tens to hundreds of millions of dollars per year in this field.
Dr. Catherine Verfaillie, who directs the University of Minnesota Stem Cell Institute, said the political turmoil surrounding this research dissuaded her from applying for federal funding when it was initially offered last year.
"Many investigators were in the same boat," she said. But now that the matter appears settled, she plans to submit a grant application.
Also Friday, President Bush defended his decision, saying he struck the right balance between the sanctity of life and the urgency of research, with enough funding to figure out whether promise will translate into a cure.
"I listened to a lot of people and did what I thought was right," Bush told ABC News from his ranch in Crawford, Texas. "I think this is the kind of decision where it does require prayer. Prayerful consideration."
In Washington, both sides expected debate over the issue to resume in Congress when lawmakers return next month.
Research proponents make up a majority of the Senate and close to it in the House, and some have pledged to push for broader funding.
"Restrictions on this lifesaving research will slow the development of the new cures that are so urgently needed by millions of patients across America," said Sen. Edward Kennedy, D-Mass.
Sen. Arlen Specter, R-Pa., said he would continue to push his legislation allowing funding with few restrictions, a measure that could be attached to spending bills that will move through Congress this fall. And Rep. Brad Sherman, D-Calif., urged Americans - especially those in wheelchairs or whose relatives suffer from Alzheimer's disease - to contact their representatives while they're home over the summer break.
But some important allies, anti-abortion Republicans who support the research, are not likely to challenge Bush's plan.
"We just have to watch this play out," said Sen. Orrin Hatch, R-Utah. He told reporters in Salt Lake City that he would like to see more stem cell lines available but Congress should hold back for now. "Let's give it a chance."
Senate Majority Leader Tom Daschle, D-S.D., predicted that "the Senate will want to take action" to open up more research funding. But he stopped short of saying he'll support it, and he praised the president's thoughtfulness.
On the other side of issue, many Christian conservatives were talking tough and warning the president that he can only go against them so many times.
Still, conservatives were markedly divided over Bush's move on stem cells. Some prominent anti-abortion groups and leaders welcomed it; others accused him of crossing a moral line. But any effort to ban funding outright didn't have the votes before Bush offered his compromise, and it would attract even less support now.
Rather, opponents hope to stave off any attempt to allow for broader funding.
"The next step would be to hold the line against any kind of coalition created to expand funding," said Deal Hudson, editor of the Catholic magazine Crisis and an informal adviser to Bush.
Ken Connor, president of the conservative Family Research Council, said it will be more difficult to argue against any embryonic stem cell research now that Bush has endorsed it in part.
"We have to help the Congress understand that nothing less than life itself is at stake," he said. "Unquestionably there's an uphill battle in Congress."