Washington (CNN) -- Traditional Senate decorum yielded to brass-knuckle politicking Friday in the health care debate as top Democrats sought to close party ranks before a key procedural vote this weekend.
Senate Democrats slammed their GOP colleagues as leaders of a counterproductive party of fear caught in an obstructionist mind-set dating back to the New Deal.
In turn, Republicans ripped Democrats for pushing a bill that conservatives say will force millions of Americans to drop insurance plans they like while jacking up premiums and doing nothing to slow spiraling medical costs.
The harsh rhetoric was backdrop for a rare Saturday night Senate vote on whether to proceed formally with floor debate on Senate Majority Leader Harry Reid's sweeping $848 billion health care bill.
The White House issued a statement Friday urging "quick action on this landmark bill.
"This legislation meets the president's criteria for health insurance reform: it provides stability and security to those with insurance; offers access to quality, affordable health care for those who do not have insurance; cuts costs for families, small businesses and the government; and does so without adding a dime to the deficit," the statement from the Executive Office of the President said, without mentioning the president by name.
The U.S. Conference of Catholic Bishops, meanwhile, issued a strongly worded letter Friday to the Senate insisting that body adopt strict limitations on insurance coverage for abortions, as the House of Representatives did two weeks ago.
The bishops called on senators to keep in place "the long-standing and widely supported federal policy against government funding of elective abortions or plans that include elective abortions."
If Republicans stay unified in opposition to the bill, Reid will need the support of all 58 Senate Democrats along with independent Sens. Bernie Sanders of Vermont and Joe Lieberman of Connecticut to reach the 60 votes necessary to overcome a filibuster.
Two key Democratic moderates -- Sens. Mary Landrieu of Louisiana and Blanche Lincoln of Arkansas -- have refused to indicate publicly if they'll back Reid. Each has expressed concern about the cost and scope of the legislation.
A third Democrat whose support had been in doubt -- Sen. Ben Nelson of Nebraska -- said Friday he will vote to start debate.
"Throughout my Senate career I have consistently rejected efforts to obstruct," Nelson said in a statement. "That's what [Saturday's] vote ... is all about."
Nelson said his decision should not be construed to mean he ultimately would vote to pass the bill.
"It is only to begin debate and an opportunity to make improvements," he said. "If you don't like a bill, why block your own opportunity to amend it?"