President Barack Obama attempted to lend his power of persuasion to the Senate’s push for health care reform Sunday, as Democratic centrists and liberals scrambled to craft key compromises on a public health insurance option and language restricting abortion funding.

Senators indicated that Obama’s appearance before a special Democratic caucus was mostly symbolic of his support for their efforts, considering he offered no specifics on the type of compromise he would like to see on contentious issues.

“It wasn’t a negotiation, it was a pep talk,— Obama said upon exiting the nearly hour-long meeting Sunday afternoon at which he took no questions from Senators in attendance.

Senators said the president encouraged Democrats to keep their eye on the ball and do something historic, saying the country would be better off and the voters would credit them if they did.

“The message was very simple: He reminded us why we’re here,— added Senate Majority Whip Dick Durbin (D-Ill.). “He reminded us why we run for office, and he reminded us how many people are counting on us to come through.—

But Sen. Ben Nelson (D-Neb.) — a key swing vote who has been working to resolve both the public option and abortion controversies — did not seem moved by the president’s appeal to history.

“For those who have made a decision to be supportive, I think he was persuasive,— said Nelson, who noted he was trying to be “diplomatic— in his statements about the president’s talk.

With no directives from the president, Nelson and other Senators went back to work almost immediately after the president’s visit, negotiating a potential compromise on the public option. Nelson indicated his proposed accord on language restricting federal funding of abortions would come up for Senate debate today.

Majority Leader Harry Reid (D-Nev.) declined to confirm that he hopes to have key compromises in hand early this week in order to start the clock ticking on the time-consuming procedural maneuvers he will need to employ to get the bill passed by Christmas.

“There’s still a few things we have to work out in the bill but issues are being narrowed as we speak,— Reid told reporters. “We’re working toward a consensus — we’re not there — but we understand how important it is we arrive at consensus and we’re going to do that just as quickly as we can.—

At press time Sunday, it was unclear if a group of moderates and liberals would reach a consensus on the public option that evening. Liberals indicated they thought an agreement was in reach, while moderates said that might not be possible Sunday.

“I’m just pleased that we’re talking. I’m pleased it’s as constructive as it is,— said Sen. Tom Carper (D-Del.), a leading moderate.

Carper acknowledged that he would like to have an agreement “fairly soon.— Members of the Democratic group include Carper, Nelson, and Sens. Blanche Lincoln (Ark.), Mark Pryor (Ark.), Mary Landrieu (La.), Charles Schumer (N.Y.), Sherrod Brown (Ohio), Jay Rockefeller (W.Va.), Tom Harkin (Iowa) and Russ Feingold (Wis.).

One of the reasons the group has been intent to finish its negotiations quickly is because of the potential lag time between an agreement and a cost-estimate from the Congressional Budget Office.

However, little information has emerged on the specific proposals the group is considering. Of the secrecy surrounding the high-pressure negotiations, Rockefeller on Saturday joked, “When [reporters] said Sen. Harkin said that [the Office of Personnel Management] was discussed, I denied even knowing who Sen. Harkin was.—

Currently, Reid appears at least four votes short of the 60 he needs to beat back a GOP-led filibuster of the bill. He will need all 60 members of the Democratic Conference or a handful of Republican defectors to ensure final passage of the bill.

Meanwhile, Reid continues private negotiations with the White House and with Members who are troubled by key aspects of the current bill to determine how to satisfy them and get to 60 votes. That includes allowing votes on amendments that could be crucial to securing the votes of centrists and liberals alike.

“Reid has a pretty good idea of what is important to individual Members and how it will affect the overall vote count,— one senior Democratic Senate aide said, adding: “Of course we sat down and mapped out what amendments were important in order to convey a message and get some of our Members in the right place.—

Sen. Olympia Snowe (R-Maine) remains a focus of Democrats as well, even as they largely meet among themselves. Snowe said Sunday she had several meetings and discussions over the weekend with Democrats.

“First and foremost they have to determine that on their side of the aisle on the question of the public option,— Snowe said.

Her vote may still prove crucial to Democrats if they cannot convince some of their own — such as Sen. Joe Lieberman (ID-Conn.) — to vote for the measure. Lieberman has threatened to filibuster most versions of a public option.

The defining vote on the bill — which Reid hopes to set up by week’s end — could come on a so-called manager’s amendment that cobbles together different proposals from a variety of Democratic Senators. That amendment is expected to include whatever accord emerges on the public option, making it a potential make-or-break vote on the overall bill.

Democrats said they expect to have to overcome three more filibusters before they can move to final passage of the bill — one on the manager’s amendment, one on a substitute amendment and one on the bill itself. The process for ending each filibuster takes at least three days, meaning Reid may have to start the process by the end of this week in order to secure passage before Christmas.

Senate Democrats are looking to use chamber rules to speed up the process in order to both find an agreement among Democrats and pass the bill no later than Dec. 31, but preferably by Dec. 24.

Though routine, Reid’s plan to attach a manager’s amendment to his $848 billion health care reform package could enable him to drastically reduce the amount of time needed for debate on disparate amendments. Each of those proposals could require several days to consider if offered on their own.

This strategy also helps the Democratic Conference avoid the prospect of some messy votes on individual issues that, as stand-alone measures, could be politically difficult for some Members to swallow.

At least some Democratic Senators seeking significant changes to the existing reform package appear content with having their proposals included in a manager’s amendment.

Sen. Mark Begich (Alaska) is working with a group of fellow Democratic freshmen on a package of cost-containment proposals he described as key to securing his vote for the final bill. But Begich, who hails from a conservative-leaning state that might resist the creation of a new, expensive government program, said he would not ask for a stand-alone vote on the forthcoming cost-containment package.

Republicans, highly critical of Reid’s health care bill, called the use of a manager’s amendment emblematic of the Democratic leadership’s approach to health care reform.

Republicans contend that the Democratic leadership is afraid to let its Members go home for the holidays without passing a bill, fearing they would hear negative feedback from their constituents and return to the Senate in January less willing to act. The GOP also tarred the manager’s amendment as symbolic of the Democrats’ backroom dealing on health care.

“There are two things going on here: There is the floor debate, and the discussion as we bring forth amendments. And there’s what Harry Reid is doing behind closed doors trying to buy his 60 votes. They’re unrelated, and the second he believes he has bought enough votes — bought 60 votes — he’ll bring it to the floor,— said Sen. John Barrasso (R-Wyo.).

Republicans concede they don’t have enough votes to prevent the Democrats from approving their health care reform bill. But believing the policy and the politics of the issue are on their side, the Senate GOP is angling to stretch out the debate over Reid’s package as long as possible to focus public attention on the matter and force Democrats into politically tough votes.

Jessica Brady contributed to this report.