.Both candidates are seeking to pivot to voters' No. 1 issue, the economy, and away from the social issues that dominated after the president announced his support for gay marriage last week.

Obama steered clear of criticizing Romney during a commencement speech at Barnard College in New York though he included a passing reference to nearby Wall Street, saying: "Some folks in the financial world have not exactly been model corporate citizens." He left the more direct skewering to surrogates and dispatched Vice President Joe Biden to Ohio to castigate Romney over his record at Bain. That was one of several events planned to highlight the Republican's role in the company he founded.

Romney, meanwhile, prepared to deliver a speech Tuesday in Iowa on reducing the huge federal deficit.

Monday's dreary global financial backdrop set the stage for a sharp debate in the coming weeks between the candidates over their competing economic philosophies, and it highlighted the public's unhappiness with big business and government institutions alike.

JPMorgan Chase's disclosure that it lost more than $2 billion on bad trading bets renewed calls for tighter oversight of the nation's biggest financial institutions, a position that Obama has supported and Romney has opposed. And world markets were tenuous as Greece weighed whether to renege on the terms of its painful austerity program and leave the Euro currency bloc. That could hurt Obama's attempts to accelerate the limping U.S. recovery.

Romney and Obama alike contend that in a nation where unemployment is hovering around 8 percent, voters will choose a president based on economic arguments. Obama is trying to persuade voters to stick with him as he heralds an economic rebound, as sluggish as it is. Romney counters that only he — with his deep background in business — knows how to jumpstart the nation's job market.

The two men have little in common in their views of how to get the country moving.

Obama has pumped money into the economy to stimulate growth and has cut some taxes though he also advocates raising taxes on the wealthiest Americans. Romney argues that lower taxes across the board and fewer government restrictions are the answer. Both are trying to win over an electorate that is furious with Wall Street and distrustful of corporations, and Obama's new campaign effort was squarely aimed at working-class voters, a group that has been reluctant to support the president in the past.

Obama's TV ad was scheduled to run in five battleground states — Iowa, Ohio, Pennsylvania, Virginia and Colorado — and was part of a larger $25 million, month-long campaign. But it was limited in scope.

Republican officials tracking the ad buy said the Obama team was airing the 2-minute spot only on Wednesday in the five states. The ad was expected to run during the evening news, directing viewers to an Obama website about Romney's economic record and a longer, 6-minute version of the ad appearing online.

As Obama's campaign was raising Romney's record in private equity, the president himself was heading to two fundraisers, including a $35,800-per-person dinner at the home of Hamilton "Tony" James, the president of Blackstone Group, the nation's largest private equity firm.

Romney's campaign, meanwhile, aggressively worked behind the scenes to counter the Obama campaign's Bain message.

It released a Web video about a successful steel company that Bain invested in called Steel Dynamics. The video shows steelworkers describing the company as the embodiment of the American dream, noting that the company grew from a workforce of 1,400 to more than 6,000. That video was not immediately planned for television.

Romney also dispatched Ed Gillespie, a senior campaign strategist, to a conference call with conservative bloggers on Monday to respond to the Obama ad. The campaign planned to frame the attacks on Romney's record at Bain as an "attack on free enterprise," and to cast the auto bailout as an example of private equity at work.

Earlier this year, Romney previewed his counterattack, saying of Obama: "He's now been a venture capitalist at Solyndra, Fisker, Tesla; and he's been a private equity guy at General Motors and Chrysler. So I'll be talking about his record when I'm facing him."

Romney, a multimillionaire, left Bain in 1999 to run the Salt Lake City Olympic Games but maintained a financial interest in the company after departing. He has said that his firm had a strong overall track record, creating jobs in prominent companies like Staples and Sports Authority, while acknowledging that some companies Bain invested in were unsuccessful.

The Obama ad, which reprises criticism leveled at Romney during the Republican primaries, focuses on one of those unsuccessful companies, GST Steel.

Bain was the majority shareholder in GST beginning in 1993. The company eventually filed for bankruptcy in 2001, a period in which the U.S. steel industry was roiled by a flood of cheap steel imports. About 750 workers lost their jobs, and were left without health benefits and with reduced pensions. The federal government was forced to put $44 million into the company's underfunded pension plan.

Bain received $12 million on its $8 million initial investment and at least $4.5 million in consulting fees, according to a January report by Reuters.

Bain Capital said Monday that it invested more than $100 million into the steel company at a time when the industry "came under enormous pressure and nearly half of all U.S. steel companies went into bankruptcy."

Criticism of Romney's time at Bain emerged during his 1994 U.S. Senate race against Sen. Edward Kennedy, D-Mass., and flared this year during the GOP presidential primaries.

Republican Newt Gingrich called Romney's role in the private equity firm "exploitive" and "not defensible."

Democrats view the current period as an important time to define Romney's economic record for general election voters. The president's defenders say he can ill afford to allow Romney to present himself as a can-do Mr. Fix-It on the economy during the summer and into the fall.

"Romney is still a blank slate for this new audience. They haven't focused on the campaign the same way primary voters have," said Tad Devine, a Democratic strategist who produced the ads for Kennedy's campaign against Romney. "This information, as it's presented, I think is going to be pretty valid."

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Associated Press writer Kasie Hunt contributed to this report.