Congressional leaders have insisted health care would get passed, even though last week's stunning loss of the Massachusetts seat long held by the late Edward Kennedy cost Democrats the 60-vote supermajority they need to deliver in the 100-member Senate. Many Democrats saw a problem with no clear solution.
"It's very possible that health care is just a stalemate and you can't solve it this year," said Sen. Mark Pryor.
If Obama and Democrats fail to pass any legislation this election year, Washington would still face the problem of millions of uninsured, rising medical costs and a dwindling trust fund for a government-run health plan for the elderly forecast to run out of money in 2017.
Obama's health care overhaul is "on life support," said Sen. Mary Landrieu, D-La., "but it still has a pulse."
The United States is the only developed country that lacks universal health care.
in Wednesday night's State of the Union address not to abandon the efforton what was once his top domestic priority - expanding coverage to millions of uninsured and reining in medical costs. But his enthusiastic words provided no specific prescription for moving forward, leaving lawmakers little better off than before.
CBS News medical correspondent Dr. Jon LaPook says the primary problem facing backers of reform is the lack of clear explanation of the proposed changes to the American public.
"Proponents of reform have lost control of the message because people think it's too complicated to understand," writes LaPook. "Confused about important details of the proposals, the public is susceptible to misrepresentations by opponents."
Senate Democratic leaders huddled Thursday to try to determine how to proceed, and the White House remained engaged in the negotiations. A Senate aide said lawmakers were hoping to decide on a legislative strategy by the end of next week.
Republican senators said senior White House officials had reached out to several in their ranks, including some conservatives, despite the unanimous Republican opposition to the far-reaching bill.
In a sign of how far health care had fallen since Obama campaigned on it, Senate Democrats devoted a weekly policy lunch Thursday to discussing jobs, not health care. Yet House and Senate leaders insisted success was still in reach.
"We're going to move forward on health reform. We're going to do health care reform this year," said Senate Majority Leader Harry Reid, a Democrat.
The leader of the House, Speaker Nancy Pelosi, acknowledged in her weekly news conference that plenty of work remained if the House was to agree to changes to the Senate bill.
Just two weeks ago House and Senate leaders were working round the clock at the White House, with Obama personally involved, to merge legislation passed separately by each chamber and finalize a bill for Obama to sign in time for his State of the Union speech. That effort was upended when Republican Scott Brown claimed Kennedy's old Senate seat.
Since then Democrats have struggled to find a way forward. The leading strategy is for the House to pass the Senate bill along with a package of changes approved by both chambers, but that idea is fraught with difficulties both political and substantive. Some Democrats favor retreating from a comprehensive overhaul and taking a less ambitious approach with a series of individual initiatives or a smaller bill.
Insurers have opposed the overhaul even though it aims to insure more than 30 million people over the next decade with a new requirement for nearly everyone to be covered.