Kirk Dornbush says he's the "last person" who should be supporting Barrack Obama.

Dornbush, president of the Atlanta-based Iconic Therapeutics Inc., has a long history with the Democrats' power couple, Bill and Hillary Clinton. He raised cash for Bill in 1992. His dad, Terry Dornbush, was ambassador to the Netherlands during Clinton's presidency. In 2000, he backed John Edwards.

But this year, it's neither Clinton nor Edwards getting his support. It's Obama, the first-term senator from Illinois.

Obama, 46, is the youngest of any of the presidential candidates this year. He's spent less time in Washington than most, and he has the least extensive resume. Yet, he's been able to attract a who's who from Wall Street and the entertainment industry.

Among his backers: Paula Crown of Chicago's $4.1 billion Henry Crown family; Mark Gallogly, founder of Centerbridge Capital Partner; Penny Prtizker, chairman of ClassicResidence by Hyatt; Dreamworks cofounders Jeffrey Katzenberg and David Geffen; and Oprah Winfrey, who threw a huge Obama bash last month at her estate in Montecito, California.

Executives and Wall Street bankers who back Obama say they believe he can be just what he portrays himself to be—an agent of change who can reach across party lines to break through political gridlock. To them, that's more important than his lack of an M.B.A. from Harvard.

Alan Solomont, C.E.O. of health and eldercare company Solomont Bailis Ventures in Massachusetts and an Obama fundraiser, thinks the business sector sees in Obama the ability to anticipate the future. "The best business and political leaders are leaders who can lead transformational change," he says.

In a survey of 258 C.E.O.'s by Chief Executive magazine released in early August, Obama was called the best Democrat for American business, while Clinton was tapped as the worst. The war on terror far outweighed issues like fiscal and tax policy, health care, and energy, when asked which issues were most important to executives surveyed.

Obama's appeal is such that he has drawn support from some unlikely quarters, including Republicans like Bobby Stein, an investor in Jacksonville, Fla., who supported President Bush in 2004. Stein has hosted events for Obama and is on the candidate's list of "bundlers"—people who have raised more than $50,000 for his campaign.

His candidacy has also drawn some young people who were not engaged in politics at all until meeting him.

"We're seeing a whole new generation of people who have never raised money before or been involved in policy development take a shot at it," says Michael Froman, an informal Obama adviser who was a Harvard Law classmate and chief of staff to Clinton Treasury Secretary Robert Rubin.

Veteran Democratic fundraiser Bob Farmer, who served as national finance chairman for four presidential campaigns before signing on to the Obama camp, says younger business executives present a golden opportunity for Obama.

"This is a new campaign with a candidate who doesn't have a history of support around the country," Farmer says, "and this is an opportunity for them to get involved on a very significant level and become part of the Obama family. I think that's an attraction."

Manish Vora, research director at Monnes, Crespi, Hardt and Co., a New York equity research firm, attended an Obama event in the Big Apple in March. The 27-year-old undecided voter said he was blown away at how many young professionals showed up; he knew 30 people there.

"You looked around the room and everyone essentially was under the age of 30. It was sort of like waiting for a concert, it was definitely a different feeling," he said.

Change is a common thread for many Obama backers. Frank Sanchez, C.E.O. of Renaissance Steel in Tampa, Florida, says backing Obama over Hillary Clinton was not "a light decision"—not least because Sanchez was an assistant secretary of transportation in Bill Clinton's administration.

For him, the decision to support Obama over Hillary was about sending a message that the U.S. would change. "I feel in this situation, we have a unique opportunity to bridge gaps in our own country and throughout the world," he says.

Financially, the Obama and Clinton camps are the two powerhouses in the eight-person Democratic primary race. Although Clinton raised more than Obama this summer—$22 million for her versus $19 million for him—the two are virtually tied in cash on hand to use for the primary elections, according to the Center for Responsive Politics.  

As of September 30, Obama, who has eschewed money from registered lobbyists and  political action committees, has raised a total of $80.3 million, while Clinton has raised $90.9 million.

According to the Campaign Finance Institute, Obama's small donors account for 28 percent of his total primary money raised from individuals; Clinton's account for 13 percent.

Supporters say these smaller contributors—many of them new to politics and the Democratic Party—responded to Obama's optimism.

"For the first time in maybe a generation, here's somebody who says, 'Government can be a good thing if we can just get our politics right. If we stop being so partisan, if we get special interests out, if we stop the gridlock in Washington, government can actually solve some of our problems,'" Solomont says.

"And that," he adds, "is what's attracting people who [Al] Gore and [John] Kerry and even [Bill] Clinton didn't necessarily attract."

Aaron Nurick, professor of management and psychology at Bentley College in Massachusetts, says Obama is seen as someone with new ideas. "Business executives are very taken with somebody who is very articulate for their vision and sort of does lay out their plan for change," he says.

Executives "enjoy hearing a message of someone they think can be a real change agent even if that person doesn't come with a real deep portfolio of experience," Nurick says. "I think they're really tired of the way things are happening in Washington. That's true for a lot of people but I think business executives are on the vanguard on that.

While courting business executives, Obama has also taken some positions that could put business support at risk. He has proposed increasing the tax burden on companies and investors to let him cut taxes on the middle class by more than $80 billion annually.

Obama was among the Democrats who have pushed to more than double the tax rate on the huge earnings of private-equity managers. When that proposal was bottled up in Congress, his reaction was swift and pointed:

 "If there was ever a doubt that Washington lobbyists don't actually represent real Americans, it's the fact that they stopped leaders of both parties from requiring elite investment firms to pay their fair share of taxes, even as middle-class families struggle to pay theirs," he said in a statement.

"When I'm president," he added, "I will close tax loopholes for big corporations, provide 90 percent of working Americans with a tax cut, and pass the strongest lobbying reform in history."

Dornbush said Obama's thoughtfulness is what drew him to the candidate. When he sat down with Obama in January and talked about his biotechnology business, which is pursuing the therapeutic use of a protein to battle macular degeneration and cancer, Dornbush said he was impressed.

"You could really just sort of see him taking this information in and processing it and really just hearing how challenging it is, drug discovery," he said. "You could see the brain sort of turning."