Updated at 11:45 p.m. Eastern time
After marathon talks, the Obama administration and Democratic leaders appeared near agreement with Nebraska Sen. Ben Nelson late Friday night to provide the crucial 60th vote needed for Senate passage of health care legislation.
Majority Leader Harry Reid intends to unveil a final package of changes in the long-debated legislation on Saturday "and is confident that it will prevail," his spokesman, Jim Manley, said in a late-night statement.
Nelson had been seeking fresh concessions to restrict access to abortion coverage in the legislation, as well as more money for his home state of Nebraska.
He told reporters "real progress" had been made, but he offered no details and said nothing final had emerged from the talks.
Reid was slightly more optimistic, referring to "significant progress" in a long day of negotiations involving numerous lawmakers as well as administration officials.
Earlier Friday, Republicans accused Democrats of bad manners, bad timing and bad health care policy on Friday, then summoned images of fire and ice for good measure as they campaigned to block passage of sweeping legislation President Obama's allies want passed by Christmas.
Unperturbed, the White House and Democrats bargained behind closed doors for hours with Sen. Ben Nelson in a search for the 60th vote needed to pass the measure. "Hopefully, we're making progress," the Nebraska Democrat said during a break in the talks.
Several officials said Nelson was seeking to ease the impact of a proposed insurance industry tax on nonprofit companies, as well as win more federal funds to cover Nebraska's cost of treating patients in Medicaid, the state-federal health care program for the poor. These officials, speaking on condition of anonymity because of the sensitivity of the talks, said the administration and Democratic leaders had offered concessions on those points.
On Friday's broadcast of the "CBS Evening News," Chief Washington Correspondent Bob Schieffer told Anchor Katie Couric that the health care debate is now "about partisanship, about getting votes, about backroom deals."
"What we're seeing here tonight, Katie, is the legislative process at its very worst," Schieffer told Couric.
Nelson has spoken openly of seeking stricter abortion curbs, and a proposed compromise on that issue has won the tentative support of Catholic hospitals. But the National Right to Life Committee objected during the day, issuing a letter that said it "in no way improves the highly objectionable provisions of the ... bill that authorize subsidies for health plans that cover elective abortion, and that authorize federal mandates for private health plans to cover elective abortion."
There was no public reaction from the U.S. Conference of Catholic Bishops, which played a significant role in drafting an abortion-related provision in the House bill.
If Republicans cared much about the outcome of negotiations, it wasn't apparent.
"This massive piece of legislation that seeks to restructure one-sixth of our economy is being written behind closed doors without input from anyone in an effort to jam it past not only the Senate but the American people before Christmas," said Sen. Mitch McConnell of Kentucky, the Republican leader.
"They are virtually thumbing their nose at the American people who are virtually screaming at us, don't pass this bill," he added.
Public opinion polls show lagging support for the measure, although Democrats argue that will change once legislation passes and consumers see benefits.
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Not all liberals saw it that way.
MoveOn.org, which helped fuel Mr. Obama's election last year, announced its opposition to the measure, citing its lack of a government-run insurance option. It urged its members to sign a petition saying, "America needs real health care reform - not a massive giveaway to the insurance companies."
The bill is designed to extend coverage to millions who lack it, prohibit the industry from denying insurance on the basis of pre-existing medical conditions and generally slow the rate of growth of medical spending nationwide.
At a cost of nearly $1 trillion over a decade, it includes hundreds of billions of dollars to defray the cost of coverage to individuals and families at lower and middle incomes.
Majority Leader Harry Reid of Nevada has been preparing a final series of revisions to the 2,074-page bill, with Senate debate expected to begin on them shortly after they are made public sometime early Saturday.
Republicans, who have been accused by Rush Limbaugh and others for failing to oppose the legislation vigorously enough, have threatened to force Senate clerks to read the entire text of the proposed changes aloud, a process that could consume eight hours or so.
At his news conference, McConnell taunted Democrats in terms that recalled Mr. Obama's campaign promise of "change we can believe in."
The health care bill, he said, "isn't change you can believe in; it's change that's astonishing. We all know that promises are made in political campaigns, but this is a complete reversal - there is no change. This is business as usual."
"Tomorrow, there's going to be a snowstorm, and we'll be coming in RVs and everything will be paralyzed as our nation's capital always is when there's a snowstorm."
He added, "But the fact is that there's a firestorm out there in America. That firestorm says stop this. Stop this."
Sen. John McCain, R-Ariz., expanded the criticism. He recalled that Sen. Joe Lieberman, I-Conn., had been turned down on Thursday when he made a routine request to speak for additional seconds on the Senate floor.
"It was objected to by the newest member of the United States Senate in a most brusque way," McCain said, a reference to Sen. Al Franken, D-Minn. "That's how the comity in this body has deteriorated. We've got to stop. We've got to stop this kind of behavior."
Aides to Franken and several other Democrats said Reid had asked members of his rank-and-file not to grant any senator additional time in view of a decision by Republicans to delay floor proceedings.