A longtime Democratic fundraiser has abandoned Barack Obama's campaign to help rival Hillary Rodham Clinton win the party's presidential nomination.

Bob Farmer, who was a top fundraiser for several past Democratic presidential candidates, had served on Obama's national finance committee.

Farmer did not respond to a request for comment after a message was left at his home in Bal Harbour, Fla. But Kirk Wager, Obama's Florida finance chair, said Farmer let him know he was switching sides without saying why.

"I thanked him," Wager said.

In response to the departure, Obama spokesman Bill Burton said, "He was not a bundler. He didn't raise any money for us, but we wish him well." Bundlers had committed to raise at least $50,000 for the campaign.

Farmer's defection to Clinton comes as her presidential campaign has been building steam. She holds a double-digit lead in national polls and a clear advantage in early voting New Hampshire. Iowa, however, still remains competitive among Clinton, Obama and John Edwards.

Clinton recently edged past Obama with an aggressive third quarter of fundraising. The New York senator holds nearly $35 million to Obama's $32 million, with primary voting just two months away.

Clinton had trailed Obama in fundraising and in money in the bank at the end of June.

For Obama, the loss of such a big name in political fundraising circles is hardly welcome news at his campaign.

Farmer was the finance chair of the Democratic National Committee during President George H.W. Bush's administration. He was a top fundraiser for Michael Dukakis in 1988, Bill Clinton in 1992 and John Kerry in 2004. Farmer served as Kerry's national treasurer in 2004, but when Kerry decided he would not seek the presidency in 2008, Farmer was one of several Kerry financial backers who chose to help Obama.

Bill Clinton chose Farmer to be his top diplomat in Bermuda, and the Clinton campaign was unhappy when Farmer picked Obama over the former first lady. Nevertheless, campaign officials continued to court him.

Farmer has donated to all the leading Democratic candidates, a practice not uncommon this election cycle. Federal Election Commission records show Farmer gave $2,300 to Obama in March, $2,300 to Edwards in June and $2,300 to Hillary Clinton in July.

The Clinton campaign did not immediately respond to requests for comment.