WASHINGTON -- By the time President Barack Obama acknowledged last Monday that his signature health care program had serious problems, it was clear the political stakes had escalated for the White House.

And so that evening, Mr. Obama gathered some of the top political advisers from his first term for a strategy session on a range of topics. The president himself spent little time on how to handle the political fallout, arguing that fixing the problems of HealthCare.gov, the website at the heart of the troubles, would take care of that challenge.

Not everyone agreed it was so simple.

In a separate huddle that night, without the president, some of these former aides -- including David Plouffe, Robert Gibbs and David Axelrod of the president's original political brain trust -- advanced a different argument to deal with what some of them saw as a looming threat.

Comparing the experience at one point to the 2010 oil spill in the Gulf of Mexico, they warned senior staffers that they needed a strategy shift -- one that involved providing as much information as possible to both Capitol Hill and the media -- or risk defections by crucial Democratic lawmakers facing re-election in 2014. Keeping the administration's allies on board was critical to saving the broader program, so maintaining Democratic cohesion represented a key first step.

By the end of the week, the administration had markedly shifted its approach, opening up more about details of the problems and holding regular news briefings in which officials identified a deadline for fixing the website and the contractor in charge of overseeing the work. They delivered private briefings to Senate staffers and House members, while White House chief of staff Denis McDonough personally called key senators to update them.

The belated turnabout underscored how the White House -- which had spent the first two weeks of the rollout focused on reopening the government and averting a debt ceiling crisis and a third week trying to deflect questions as they enlisted help to fix the system -- has been forced to scramble to fend off a back-door assault from Democrats on the president's signature legislative achievement. With sparse information about the website's problems at the outset, senior administration officials are now working to repair fissures in a party that managed to present a united front until last week.

"The stakes are high because of the politics of it," said Rep. Gerald Connolly, D-Va., a White House ally who has criticized the contracting process. "I think the White House understands that it's important to have transparency, so we're not unnecessarily eroding confidence in the program."

For three weeks the administration provided few details about the enrollment system's operations, including what went wrong and how many consumers were able to enroll. While it is still not releasing enrollment figures or identifying who specifically is repairing the site, by Friday Jeff Zients -- the former management consultant and Obama budget official brought in by the White House to oversee the effort -- assured reporters it would be functioning smoothly by the end of November.

"It's going to take a lot of work and some time, but there is a clear path forward," he said.

Even as the administration launched a more robust defense of the federal health insurance marketplace -- dispatching staffers to Capitol Hill for closed-door briefings and firing off memos to lawmakers' offices with the underlined talking point, "The website is fixable" -- some jittery Democrats are pressing for changes to the system.

Sen. Jeanne Shaheen, D-N.H., and nine other Democrats -- four of whom are facing tough re-election fights in conservative states -- asked Health and Human Services Secretary Kathleen Sebelius on Friday to extend the program's enrollment period beyond March 31 to ensure Americans aren't penalizing for failing to sign up for insurance by then.

Separately, Sen. Joe Manchin III, D-W.Va., is working with Sen. Johnny Isakson, R-Ga., to press for a one-year delay in the individual mandate that Americans buy insurance or pay a $95 penalty.

"All we're postponing is the crime and a fine," Mr. Manchin said in an interview Thursday. "I'm not giving up. You have to make it better."

But these proposals could undermine the basis on which insurers made their premium estimates, thereby jeopardizing the overall system.

Robert Zirkelbach, spokesman for America's Health Insurance Plans, said insurers were comfortable with the administration's decision Wednesday night to waive the penalty for any American who signs up for insurance by March 31, since "that is consistent with what health plans assumed with their premium rates for next year."

"But delaying the individual mandate or extending the enrollment period, going beyond that, would be problematic and could be destabilizing for insurance markets," Mr. Zirkelbach added.