US senators are set to begin a debate on President Obama's massive health care reform bill which is on the top of his list, but faces opposition from divided Democrats apart from Republicans.
Debate is to begin Monday morning on the measure to overhaul the US health care system, at an estimated cost of 848 billion dollars through 2019, but a final Senate vote on the bill is not expected for a month at the earliest.
The administration hailed the November 22 vote that cleared the way for debate to begin, but Senate Majority leader Harry Reid faces a tough challenge constructing a coalition strong enough to get the bill out of the Senate.
He can count on almost unanimous opposition to the measure from Republicans, one of whom has vowed a "holy war" against the bill.
The Republican Party wants to kill the bill or at least delay the battle until 2010, when midterm elections might make it more difficult for centrist Democrats to support the reform.
But even ahead of election season, Reid and the White House face an uphill struggle to build the 60-vote bloc they need to overcome parliamentary delaying tactics and ensure the bill passes into law.
Three key Democratic senators have expressed strong opposition to various measures in the bill, as has an independent lawmaker who usually votes with the Democratic Party.
Senators Mary Landrieu of Louisiana and Blanche Lincoln of Arkansas are among those firmly against a government-administered health program or "public option."
"I'm promising my colleagues that I'm prepared to vote against moving to the next stage of consideration as long as a government-run public option is included," Lincoln said last week.
Independent Senator Joseph Lieberman, a former Democrat who usually votes with the party, has said he would vote against a bill including a public option "as a matter of conscience."
Some Democrats believe the bill is simply too expensive, though estimates say it would cut the US budget by 130 billion dollars by 2019.
Others, including Senator Ben Nelson of Nebraska, will not support a bill without a provision sharply limiting funding for abortion, akin to a provision included in the reform bill that passed the House of Representatives.
With such tenuous Democratic backing, Reid and the White House are courting several moderate Republicans whose support could also help them sell the bill as a bipartisan measure.
Support from Maine Republican Senators Olympia Snowe and Susan Collins are top priorities for Democrats, and Snowe has already publicly indicated some willingness to vote in favor of health reform if certain conditions are met.
If Reid can eventually muster the votes needed to pass legislation out of the Senate, negotiators from the House and Senate will meet to hammer out a reconciliation bill.
The consensus measure would then face new votes in both chambers before going to Obama for his signature.
The US president, who has made extending health coverage to some 47 million uninsured Americans a key legislative priority, has said he wants to sign a bill by the end of this year.