The superdelegates - various party officials including all Democratic governors and members of Congress - are poised to decide the nomination because neither candidate has a realistic chance of winning enough "pledged" delegates in the primaries and caucuses remaining before the late-August convention. Nearly 450 superdelegates have declared their choices, breaking in Clinton's favor but not by enough to negate Obama's overall delegate lead.
He leads in delegates, 1,567-1,462, even though she maintains a 242-207 edge in superdelegates. It takes 2,025 to win the nomination.
Another 270 or so superdelegates remain undeclared, and scores of them told The Associated Press on Wednesday they intend to stay that way, at least through the Pennsylvania primary seven weeks away.
They fall into two basic groups: those who see the protracted Obama-Clinton struggle as good for the party, and those who fear it will damage the eventual survivor and help Republican John McCain, who clinched the nomination Tuesday.
"I think it hurts the party long-term, and I think it hurts the party's eventual nominee," said Rep. Allen Boyd, D-Fla.
So, should superdelegates shout "enough," and decisively break for Clinton or Obama? the AP asked Boyd in its bid to survey all 720 superdelegates (a number that will grow before the convention).
No, said Boyd, who remains uncommitted. "That's something that has to be decided between the two candidates," he said. "Neither one of them will probably give in, but it's going to be very difficult for the eventual nominee."
Such comments frustrate many superdelegates openly backing Obama, an Illinois senator.
"I don't think it's at all good for the party for the race to go on," said Alan Solomont of Massachusetts, a top fundraiser for Obama. "As long as our race goes on and the Republicans have a nominee," he said of McCain, "it's going to give him a free ride and give him an opportunity to begin to campaign against the Democratic nominee, whoever it may be."
Other pro-Obama superdelegates are more sanguine.
"The conventional wisdom is that continuing the primaries is counterproductive," said Rep. Chet Edwards, D-Texas, "but I think these primaries are creating a lot of grass-roots energy for Democrats, and Senator Clinton has every right to continue on."
Not surprisingly, most pro-Clinton superdelegates are eager for their undeclared colleagues to stay on the sidelines. That gives the New York senator time to keep criticizing Obama and possibly win Pennsylvania and later races.
"The momentum has switched, the race has turned," said Pennsylvania Democratic Party chairman and pro-Clinton superdelegate T.J. Rooney. Obama's inability to "close the deal" by winning Texas and Ohio raises questions about his electability, Rooney said, and "it's a new day" for Clinton.
Elisa Parker, vice chairwoman of the Tennessee Democratic Party and a pro-Clinton superdelegate, said: "I do think it could go to the convention. But I'm not really worried about that, because I think it could help her the longer this goes."
Dozens of undeclared superdelegates said a protracted campaign is not a problem.
"Certainly it would be nice if we did have our ticket together," said Nancy DiNardo, the party chair in Connecticut.
"But it's not necessary yet. We have a few more states that still have to weigh in, and I think it still generates excitement. It's like the pennant race, or even the Super Bowl."
"I think John McCain just isn't going to get the attention any more," she said.
Numerous superdelegates said a protracted Clinton-Obama battle is a problem only if the campaign turns sharply negative. But that's a distinct possibility, according to political strategists who say Clinton's only hope of overtaking Obama is to criticize him and hope he makes a major error or falls victim to a damaging revelation.
Sen. Claire McCaskill of Missouri, an Obama supporter, said: "There's no question that if Senator Clinton is running the Republican National Committee's ads, that helps Senator McCain."
"That's why there will be pressure brought to bear on the Clinton family about the type of campaign they choose to run from here on out," she said.
Rep. Elijah Cummings, D-Md., is among the pro-Obama superdelegates urging undeclared colleagues to back the front-runner, and soon.
"You have this whole group of people who are for Obama but were waiting to see what happened last night, and they're trying to decide whether to stay in a holding pattern or come out for him," said Cummings, making a claim that Clinton supporters question.
Stephanie Cutter, who is not a superdelegate but helped run John Kerry's 2004 presidential campaign, said the undeclared players are in a difficult spot. "Some superdelegates will come off the fence," she said, "but I think we're in this for at least the next seven weeks."
Or maybe longer.
Former Democratic National Committee Chairman Charles Manatt, who backs Clinton, said it is hard to argue for a pro-Obama rush after the Texas and Ohio results.
"She just won big victories," he said. "Who knows, it could go to Puerto Rico."
The Puerto Rico caucus is June 1.
