"The problem is the moderate Democrats who voted for this bill a few months back, but now the political environment has changed dramatically," Dowd said. "I don't know if she [Pelosi] can keep those."
Obama and Pelosi need to pick up those votes and persuade some of their skeptical party members, including moderate, so-called Blue Dog Democrats, some of whom want more restrictive abortion language in the bill and are wary of the bill's price tag. The president and Pelosi will also try to woo retiring Democrats and lawmakers who are almost certain to lose this November anyway.
In November, 220 House members voted for the health care bill, but the one Republican who voted for it has since retracted his support. One congressman died and two others have resigned.
That Senate version of the bill will need a majority of 217 votes to pass the House. The Democrats are staring with 216. If the president can get 217 votes, the bill will go to the Senate where the only path to victory is to use a controversial voting rule that requires 51 votes.
All the while, the president and Democrats will face Republican and insurance industry attacks, and the winds of public opinion blowing against the bill.
Republicans continue to call for Democrats to start over. But with vast ideological differences, it appears that the Democrats have decided to forge ahead or face the political and economic costs of inaction.
"I have to tell you, as a Democrat, that frightens me," Carville said. "When you're a governing party, and you have a majority like we do, and you have a president, sometimes you got to step up and do something. I suspect this is one of those times."
"It's crunch time out there," he added. "If this doesn't get done, it will hurt the Democratic Party. There's no doubt about that."