Many of the amateur fundraisers who helped finance President Obama's 2008 campaign will not return for the 2012 push, disillusioned by a perception that what was once a grassroots, outsider campaign has morphed into a big-money operation, Politico reported.

Obama campaign officials have denied that their supports have lost any of their vigor, noting that much of the $86 million pulled in so far has come from small individual donations. But some bundlers who waded into the political fundraising world for the first time in 2008 will not be returning to an operation they think has become too mercenary and reliant on traditional big donors.

It's a political machine now, said Pete Garcia, the chief financial officer of a Washington State biotech company who raised more than $200,0000 in 2008. I wasn't doing it to be an ambassador or anything like that. I was doing it because I strongly believed in his message. I just thought that he would be a little more different than he is.

The shift is occuring in part because Obama is now an incumbent, so professional fundraisers who supported Hillary Clinton in 2008 have automatically migrated to his camp. There is a sense among people like Garcia, who got their first taste of fundraising during the idealism of the 2008 campaign, that the Clinton operatives are bloodless members of the establishment.

I would bet you that 90 something [of former bundlers] are guys like me -- we still love the president, but we did it because we believe in the cause, said another early, large-scale bundler. But now we're getting bumped by the old Clinton folks. This is what they do for a living. They're animals and they're political whores and they want the access and the credit.

The financial stakes are also vastly higher, with Obama seeking a total of $1 billion in contributions. Obama initially disparaged the stampede of special interest money that helped propel Republicans to sweeping gains in 2010, but since then Democrats have worked to build a formidable fundraising machine that will also rely on massive undisclosed funding. The powerful Republican political action committee cast 2012 as a David and Goliath battle given the Obama campaign's virtually limitless financial resources.

Obama is also appealing to special interests that could prove central to his fundraising fortunes. Gay advocates, pleased by stances like his backing of a bill to repeal the Defense of Marriage Act, have emerged as important allies. He has also worked to court the Wall Street donors who were among his top backers in 2008, inviting high profile financial executives to the White House and attending fundraising events. Part of the exodus of former supporters likely reflects the fact that as incumbent, Obama is running on his record more than on his promise.

It was much easier when he was Barack Obama, the mostly unknown who spoke wonderfully and said great things and was charismatic, said Rob Tessler, a New York-based lawyer and a member of the president's tri-state fundraising committee. Once you've been in office -- being reelected is a lot harder.