Priorities USA Action, a super PAC supporting President Barack Obama, released a new ad Thursday hammering presumptive GOP nominee Mitt Romney over his record at Bain Capital.

"But for every company he drove into the ground, Romney averaged a $92 million dollar profit," says a narrator. "Now he says his business experience would make him a good president?"

"If Romney Wins, the middle class loses."

The ad is fifth in a $10 million ad buy running in the swing states of Colorado, Florida, Pennsylvania, Virginia and Ohio.

The ad is part of a pattern of the Obama campaign and its allies painting Romney as a corporate raider. The former Massachusetts governor is running on his business experience, saying it has prepared him to be president in a sagging economy.

Despite protestations from certain Democrats, such as Massachusetts Gov. Deval Patrick and Newark, N.J. Mayor Cory Booker, there is evidence that these attacks against Romney are working, as Obama's lead has expanded recently in Ohio and Pennsylvania.

Romney has faced attacks on his record at the private equity firm since he ran for U.S. Senate against Ted Kennedy in 1994. However, his campaign's recent pushback against the attacks hasn't worked. On Wednesday, the campaign tried and failed to get the Washington Post to retract a story on Bain Capital's outsourcing of jobs. It also posted but quickly pulled a video defending GS Steel, a company Bain took over that has been the focus of attack ads by Priorities USA and the Obama campaign.