As President Obama takes the podium in the Capitol tonight, members of both parties are looking ahead to the next legislative challenge and wondering whether the stimulus bill -- which began with noble goals of bipartisanship but ended in an acrimonious round of finger-pointing -- will set the tone for the early days of the administration.

All signs are pointing to health care reform as the next issue topping the agenda for the White House and Congress. So will Republican senators close ranks against the popular president on health care, leaving the majority Democrats to horse-trade their way to a slim 60-vote victory?

Senior GOP senators have a clear, and perhaps surprising, answer to that question: they're ready to work with the president's party on health care.

"There is an acknowledgment on both sides that something has to be done" on health care, Senate GOP Conference Vice Chairman John Thune (SD) told me, adding openly that more than three members of his party "are gettable" for a health reform bill this year

Another Senate Republican leader, third-ranked Lamar Alexander (TN), agreed that the minority is coming to the table on health care with an open mind: "Republicans are as interested as Democrats in helping every American find health insurance ... Our goals are very much the same as the Democratic goals."

Of course, the two parties are almost guaranteed to disagree on the finer points of delivering affordable health care to the 45 million Americans who are now uninsured. But senior Republicans' outlook on health care is a stark contrast to the stimulus debate, when all but four minority senators cast votes against the very notion of government spending to resuscitate the economy.

"You could get a lot more than three Republicans" to back the coming health reform bill, another Senate GOP leader, Policy Committee Chairman John Ensign (NV), told me. The key, as he described it, is the process Democrats use for consideration of the measure.

President Obama will make the broad case tonight, but two powerful Senate chairmen, Max Baucus (MT) of the Finance Committee and Edward Kennedy (MA) of the health committee, will ultimately do the heavy lifting to produce legislation after lengthy debate.

If Baucus and Kennedy run into trouble reconciling their health bills, or if political pressure on President Obama grows too great, what Washington calls "regular order" could fall by the wayside and a leadership-driven product could be pushed to a vote in the Senate. If that happens, Democrats can expect to have a harder time breaking a GOP filibuster than they did on the stimulus.

"If they don't go through regular order on comprehensive health care reform, it won't stand a chance," Sen. Richard Burr (R-NC) said, predicting a GOP backlash against a quickie health bill that "makes the public outrage over the stimulus seem light."

Even Sen. Susan Collins (ME), one of the three Republicans who insisted on a seat at the stimulus negotiating table in exchange for their votes, said that regular order would be pivotal to winning her support for health reform.

"When you get the best legislation is [after] extensive hearings and regular committee consideration," she said, telling me that regular order on health care is "my expectation and hope."

Progressive voters -- and a fair share of Democratic lawmakers -- are conditioned to take Republican openness with a full shaker of salt. But if Democrats call the GOP's bluff and steer health reform through the committee process, Republicans will be dared to translate their words into action.