Now the focus is on Hillary Rodham Clinton and how she handles the final stages of her quest for her party's presidential nomination.

Confronted by arithmetic that borders on the impossible, Clinton has opted to keep going, playing for time and hoping that someone or something comes along to transform the contest.

And no one, it seems, has any intention of trying to stop her, so long as she doesn't do any major damage to Obama's prospects as the party's likely standard-bearer - which she hasn't thus far.

U.S. Rep. Jason Altmire, who represents a district outside Pittsburgh, voiced the views of many congressional Democrats by saying that Clinton has "earned the right to continue to campaign to see if she can close the gap."

The sentiment among some Democratic leaders goes beyond that.

They have come to believe that Clinton's staying in the race - if only through the end of the primaries three weeks from now - may not be the worst scenario for party unity, assuming everyone stays on best behavior.

"Her supporters would take it very badly if they felt she were being unfairly forced out by Nancy Pelosi or Al Gore or other party elders," said Steve Murphy, a Democratic strategist who worked on the presidential campaign of Bill Richardson.

Through their silence, Obama and his surrogates have expressed their concurrence, making no move to push out the woman who was once considered her party's inevitable nominee.

In interviews last week, the Illinois senator described her with such words as tireless, smart, capable and formidable and expressed no impatience with her staying in the race. He said she'd have to be on anyone's short list as a would-be running mate and resisted attempts to describe himself as the presumptive nominee.

Clinton, in the wake of her disappointing showings in North Carolina and Indiana on Tuesday, has stopped attacking Obama - although she created a stir when she told USA Today that his support among "white Americans is weakening again."

In her speeches, she has limited herself to laying out her proposals and making the case to keep going.

"There have been some folks who have been arguing that we should stop voting," Clinton told a crowd in Sioux Falls, S.D., last week, recalling earlier moments in the race when she seemed on the verge of defeat. "I think the more democracy we have, the better."

She has continued, too, to assert that she has shown herself to be the stronger candidate against John McCain and the Republicans.

At one stop, she listed the battleground states in which she has won primaries, naming Pennsylvania, Ohio, Arkansas, New Jersey, New Mexico, New Hampshire, Michigan and Florida.

"I'm winning Catholic voters and Hispanic voters and blue-collar workers and seniors, the kind of people Sen. McCain will be fighting for in the general election," she said in Charleston, W. Va.

Her aides say there have been no internal conversations about her dropping out. Communications director Howard Wolfson says that she believes she still can win.

"Among her core supporters, it's as gung-ho as it's ever been," said Philadelphia lawyer Alan Kessler, a Clinton fund-raiser. "We're all in this to see how it plays out."

Another prominent Clinton backer, Philadelphia lawyer Mark Aronchick, said her continued candidacy is good for the party, even if she ultimately can't persuade the superdelegates that she'd be the stronger nominee. Stopping the process now, he said, might feed a sense that her candidacy has been slighted.

"We're talking about identity politics on both sides," Aronchick said, "and the identity politics on the Clinton side among women - the passion, the zeal, the commitment, the sense of history, the sense of a movement - hasn't gotten as much attention and respect as it deserves, as she deserves.. . .

"There's no reason not to want to have all the results, all of the facts, for the superdelegates to consider," he said. "There's plenty of time to come together."

How long Clinton stays at it will depend on a number of factors, including her ability to fund her campaign, either through contributions or her own resources, and to keep the steady drip of superdelegates to Obama from becoming a flood.

In addition, there's the question of how long she can keep going out there day after day in the face of a broad consensus that the game is over. A big win for her in West Virginia on Tuesday might lift her spirits, if they need lifting.

It's not clear how or when the end will come. But here are dates to keep in mind:

On May 20, after the votes are counted in Kentucky and Oregon, Obama almost surely will have an absolute majority of the pledged delegates available in the primaries and caucuses, not counting the disputed contests in Michigan and Florida. His aides have indicated he might declare victory at that point.

On May 31, a panel of the Democratic National Committee will meet in Washington to address the Michigan and Florida situations, which the Clinton campaign talks about constantly. A resolution of this mess is likely, but it won't wipe out Obama's delegate lead. He currently leads by more than 160 delegates, according to the Associated Press.

On June 3, the final primaries in South Dakota and Montana take place, and undeclared superdelegates will be expected to declare shortly thereafter, deciding the nomination. Terry McAuliffe, Clinton's campaign chairman, has acknowledged that will happen, saying he does not see the battle going to the convention in August.

Donna Brazile, who ran Gore's presidential campaign is 2000, has spoken of the campaign ending on a "joyful" note. Most Democrats would settle for civil and restrained, the path Clinton seems to have chosen.

At least for now.

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