A Scramble for Edwards and Giuliani Fundraisers

"I know Senator Clinton from years past, and I've supported both she and her husband in the past, so it's an easy transition for me," McKernan said.

On the Republican side, the outreach to Giuliani supporters by aides to Sen. John McCain (Ariz.) and former Massachusetts governor Mitt Romney has been less organized.

Hug said he had not heard from either campaign in recent days. Robert W. Naylor, a Sacramento lawyer, said that he received one call from a friend who backs Romney, but that it came too late. He had already reached out to McCain's camp.

Naylor had planned to serve as a delegate for Giuliani but said yesterday that he is getting behind McCain because "he is, of the remaining candidates, the most likely to be able to attract independents and Democrats."

The urgency of finding new donors for the candidates still standing cannot be understated. McCain finished 2007 with $2.9 million in cash and $4.5 million in debts, according to his campaign's year-end financial report. He has since raised about $7 million, his campaign aides have said, adding that he has seen fundraising accelerate in the aftermath of his South Carolina and Florida primary victories.

Naylor said he received a call on Tuesday saying that a McCain fundraising breakfast planned for San Francisco had to be moved to a larger venue because of new interest in the event.

But with contests in more than 20 states on Tuesday, including primaries in some of the nation's most costly media markets, the candidates' immediate needs are enormous, even for fundraising juggernauts such as the Obama and Clinton campaigns.

Terence R. McAuliffe, the chairman of Clinton's campaign, said he is urging recruits from the Edwards camp to begin making calls immediately.

After two days of meetings with trial lawyers, McAuliffe said he has secured support from a handful of former Edwards backers who have the potential to raise $100,000 each before Super Tuesday.

"They have a huge reach," McAuliffe said. "They can raise money very quickly."

Still, not all of those who worked hard on Edwards's behalf are ready to make the leap to another campaign just yet.

Robert B. Crowe, a Boston lawyer who served as a top fundraiser for Sen. John F. Kerry (Mass.) in 2004 and who has not yet committed to helping a Democratic candidate, said he knows several people who simply are not ready to move to a new candidate.

"It's hard, if you've given all you have to a campaign, to get ginned up for another candidate and start that process all over again," Crowe said. "And I suspect it is especially hard given how close we are now to Super Tuesday."