Obama's campaign managers made a conscious decision not to apologize to potential donors for his criticism of private equity, even behind the scenes, according to several backers who asked not to be identified because the talks were private. The administration figured any loss in contributions from the financial-services industry could be made up with money from grassroots fundraising, Hollywood celebrities and technology- company moguls.

"Mitt Romney has actively fundraised off the fact that he would repeal Wall Street reform and let Wall Street write its own rules again, regardless of the consequences for middle-class families," said Ben LaBolt, an Obama campaign spokesman. "The president believed it was necessary to take steps to ensure that the financial crisis that crashed our economy and threatened the security of the middle class isn't repeated -- and most Americans agree with him."

Workforce Cuts

In May, the Obama campaign began a series of ads criticizing Romney's record as a co-founder and chief executive officer of Boston-based Bain Capital.

One Web video, a mini-documentary that lasts almost six minutes, focused on SCM Office Supplies Inc. of Marion, Indiana, where 350 factory workers got fired after Bain Capital-owned American Pad & Paper LLC bought the company in 1994. The company, known as Ampad, filed for bankruptcy in 2000.

"Bain and Mitt Romney did not care about us as workers," one former employee says in the ad.

"Through more than a generation of investing, Bain Capital has been focused on growing great companies and improving their operations," Bain said in a statement issued through spokesman Alex Stanton. "We understand that in a political campaign some may distort our investment activity by cherry-picking a few negative situations while ignoring our overall track record."

'Nauseating' Attacks

Cory Booker, the mayor of Newark, New Jersey, called attacks on private equity "nauseating." Steven Rattner, who founded a buyout firm and later worked on Obama's bailout of the auto industry, also defended the business. Former president Bill Clinton, who served as a senior advisor to investor Ron Burkle's Yucaipa Cos., said Romney's business record is "sterling."

Romney's presence in the race also is bringing scrutiny to the beneficial tax treatment given to private-equity firms and to some hedge funds.

Under current law, a manager's profits from a private-equity fund, known as carried interest, are considered capital gains and therefore taxed at 15 percent. The Private Equity Growth Capital Council, a trade group for the industry, spent about $4.65 million lobbying to keep this tax treatment, and on issues such as Dodd-Frank, even in the face of sluggish economic growth and mounting pressure to cut the U.S. deficit.

The industry group this year produced a series of six videos called "Private Equity at Work" that are designed to highlight the industry's role in expanding companies, and it set up 49 visits this year between private equity-owned companies and members of Congress or their staffs.