Despite a Senate majority, health care reform will be no easy pass as moderate Democrats on the fence about the legislation threaten to halt the bill if their demands aren't met.
The bill cleared its first hurdle in the Senate Saturday night by a 60-39 vote strictly along party-lines.
But final passage is leaning partly on four lawmakers-- Democratic Sens. Ben Nelson of Nebraska, Mary Landrieu of Louisiana and Blanche Lincoln of Arkansas and Connecticut independent Joe Lieberman.
Each agreed to open debate on the legislation, but now warn they may not support the bill in the end.
"I don't want a big-government, Washington-run operation that would undermine the ... private insurance that 200 million Americans now have," Sen. Nelson said Sunday.
Their main concern is the "option-out" public option for government-run health care included in the House version. Opponents say it will do nothing more than drive up health care costs and eventually hurt businesses.
"I don't want to fix the problems in our health care system in a way that creates more of an economic crisis," Lieberman said.
The rare Saturday session vote cleared the way for what is sure to be a bruising debate beginning the week after Thanksgiving.
Democrats squeaked by a looming GOP showdown with the unified 60 vote majority needed to overcome a filibuster.
Just hours before roll call, Dems sealed the 60 votes needed after Sens. Blanche Lincoln of Arkansas and Mary Landrieu of Louisiana both said they would vote to advance the bill.
Of the Republicans, 39 voted against the move. Republican Sen. George Voinovich of Ohio missed the vote.
Reaction from the White House came minutes after the Democrats victory.
"Tonight's historic vote brings us one step closer to ending insurance company abuses, reining in spiraling health care costs, providing stability and security to those with health insurance, and extending quality health coverage to those who lack it," The White House said in a released statement. "The President looks forward to a thorough and productive debate."