Barack Obama is narrowing Hillary Rodham Clinton's once-commanding lead among the Democratic superdelegates as they follow the voters.
In the past two weeks, 25 unpledged superdelegates have climbed aboard his presidential campaign, while Clinton has lost two.
Superdelegates are Democratic office holders and party officials who automatically attend the national convention and can vote for whomever they choose. As Obama has reeled off 11 straight primary victories, some of them are rethinking their public commitments.
Clinton still leads among superdelegates - 241 to 181, according to an Associated Press survey.
John Perez, a Californian who first endorsed John Edwards and then backed Clinton, now says he is undecided.
"Given where the race is at right now, I think it's very important for us to play a role around bringing the party together around the candidate that people have chosen, as opposed to advocating for our own choice," he said.
The nearly 800 Democratic superdelegates are an important force in the close nomination race, and both campaigns are furiously lobbying them.
"Michelle Obama and I are playing phone tag," said Audra Ostergard of Nebraska.
Billi Gosh, a Vermont superdelegate who backs Clinton, got a phone call from her this week. "As superdelegates, we have the opportunity to change our mind, so she's just connecting with me," Gosh said.
Obama has piled up the most victories in primaries and caucuses, giving him the overall lead in delegates, 1,362 to 1,266.5. Clinton's half delegate came from a global primary sponsored by the Democrats Abroad.
It takes 2,025 delegates to secure the nomination at this summer's national convention in Denver. If Clinton and Obama continue to split delegates in elections, neither will reach the mark without support from the superdelegates.
That has the campaigns fighting over the proper role for superdelegates, who can support any candidate they want. Obama argues it would be unfair for them to go against the outcome of the primaries and caucuses.
"I think it is important, given how hard Sen. Clinton and I have been working, that these primaries and caucuses count for something," Obama said during Thursday night's debate in Austin, Texas.
Clinton argues that superdelegates should exercise independent judgment.
"These are the rules that are followed, and you know, I think that it will sort itself out," she said during the debate. "We will have a nominee, and we will have a unified Democratic Party, and we will go on to victory in November."
The Democratic Party has named about 720 of its 796 superdelegates. The rest will be chosen at state party conventions in the spring. Reporters have interviewed 95 percent of the named delegates, with the most recent round of interviews taking place this week.
The superdelegates make up about a fifth of the overall delegates. As Democratic senators, both Clinton and Obama are superdelegates.
So is Cincinnati Mayor Mark Mallory, which is one reason his phone rings often. A phone call from former President Bill Clinton interrupted his dinner on a recent Saturday.
"I continue to get calls from mayors, congresspeople, governors urging me one way or another," said Mallory, who is still mulling his decision. "The celebrities will be next. I guess Oprah will call me."