President Barack Obama's drive to revamp US health care could face a critical test vote in the US Senate, where lawmakers await an influential report on the plan's cost and overall impact.
Obama's Democratic allies hope to pass sweeping legislation to enact the president's top domestic priority this year, but face intra-party feuds over the volatile issue of abortion and the government's proper role.
Democratic Senate Majority Leader Harry Reid hopes to set the stage to launch formal debate next week, after the non-partisan Congressional Budget Office (CBO) issues a report on the bill's price tag.
"The goal, still, is to at least start the debate before the Thanksgiving recess," which begins November 23, said Reid spokesman Jim Manley.
Doing so would require a vote on whether to proceed to the health care debate, with support of 60 senators needed to ensure passage over any parliamentary delaying tactics from Republicans bitterly opposed to the plan.
That could prove a risky test of support for the legislation: several swing-vote Democrats and one independent who often sides with them have signaled they may not support launching the debate at this point.
The doubters chiefly object to the inclusion of a government-backed health insurance program -- popularly known as a "public option" -- to compete with private insurers.
And at least one Democratic senator, Ben Nelson of Nebraska, has said he will withhold his support unless the Senate bill tightens curbs on federal monies going to pay for health plans that cover abortion.
Nelson's comments came after the House of Representatives approved an amendment sharply toughening such restrictions, a step seen as key to winning over some anti-abortion Democrats' support for the bill, which passed last week by a narrow 220-215 vote.
But Democrats and outside groups that favor abortion rights have indicated they will fight to have such limits removed from any final legislation before it goes to Obama to sign into law.
Republicans have complained that Reid, who sent the CBO a bill that blended work by two key committees but did not release the legislation publicly, is trying to rush the measure through the Senate.
Republican Senate Minority Leader Mitch McConnell pushed last week for the Senate bill to be available online for 72 hours so lawmakers and the public "can take a look at it" before formal debate beings.
If, as expected, the Senate and House of Representatives approve rival versions of the legislation, they would have to forge a compromise bill and approve it in order to send it to Obama to sign into law.
On Friday, a group that supports the White House approach, Health Care for America Now, launched a television advertising campaign to pressure reluctant senators from Arkansas and Nebraska to vote yes on starting the debate.
The United States is the only industrialized democracy that does not ensure that all of its citizens have health care coverage, with an estimated 36 million Americans uninsured.
And Washington spends vastly more on health care -- both per person and as a share of national income as measured by gross domestic product -- than other industrialized democracies, with no meaningful advantage in quality of care, according to the Organization for Economic Cooperation and Development.