Obama and Clinton campaign together

How is he doing at winning over her supporters – and tapping into her formidable fundraising network? What might she get in return?

It will be the photo-op seen 'round the world: Barack Obama and Hillary Rodham Clinton, together Friday on stage, a picture of Democratic unity in the town of Unity – the New Hampshire burg where each got 107 votes in the January primary.

But just as important for Senator Obama, in his quest to reunify his party after a divisive primary season, will be a private meeting the night before with a few dozen of Senator Clinton's top fundraisers .

While polls indicate that the rate of "defections" – Democrats who intend to vote for presumed GOP nominee John McCain – is already approaching the usual rate of the recent elections, Obama can take nothing for granted. And, having decided to forgo public financing on the wager that he can raise far more money on his own, now he has to deliver. Clinton donors, and their fundraising prowess, are key to that equation.

"Unity is the key word," says Democratic strategist Peter Fenn. "On the Hillary side, some of these people are angry and tired and a little bitter. But they will be a lot less so if Obama can assist her."

In a teleconference on Tuesday, Obama asked his top fundraisers to consider helping the former first lady pay back some of her campaign debt. She ended May $22.5 million in the hole, but at least $12 million is money she loaned to herself. Obama is asking his money bundlers to help her pay off money she owes to outside vendors, totaling at least $10 million.

Obama has yet to ask his vast network of small-money donors to pitch in for Clinton. That might be a riskier proposition for the senator from Illinois. Some rank-and-file Obama supporters viscerally do not like Clinton; to some, she does not represent change. She also voted to authorize US military action in Iraq, a move that ended up paving the way for Obama's antiwar candidacy.

But now that Obama has locked up the Democratic nomination, both camps are hoping that all can be forgiven, and that the campaign strengths of both Clintons can be deployed to return a Democrat to the White House for the first time since the Clintons themselves lived there.

After a period of silence, former President Clinton endorsed Obama on Tuesday. It was not the full-throated statement that his wife offered on June 7, but it got the job done.

After a bruising primary season, where charges of racism and sexism flew fast and furious, Democratic voters are unifying more quickly than expected, analysts say. In the past four presidential elections, there was a consistent 10 or 11 percent "defection rate" of Democrats voting for the Republican nominee. Already, Obama is nearing that range in recent polls, some taken before his June 3 clinch of the nomination.

Senator McCain, who also faces skepticism within his own party, is doing even better at uniting Republicans. His defection rate ranges from 8 percent to 12 percent. In the last two presidential races, both won by his party, the defection rate was 8 percent (2000) and 6 percent (2004), according to exit polls.

For Obama, the deep disappointment of many Clinton supporters remains an obstacle. In interviews, they said they would vote for Obama, but were not prepared to do much beyond that.

"I won't vote against him, but I just don't have the heart to put into this," says Marjorie Signer, president of Virginia NOW.

William Klein, a Democratic publicist based in Silver Spring, Md., says that eventually, he'll get excited about Obama, "but I'll also continue to worry about him winning battleground states."

"The Hillary people who say they're for McCain, I guess they remind me of the Perot voters who never voted before and never will again," says Mr. Klein, referring to the independent candidacy of Ross Perot in 1992 and 1996. "They're not very political. Hopefully, the Democratic advertising and marketing will work by November, and they'll realize they don't want to vote for McCain."