NEWTON, Iowa — President Obama will appear Thursday evening at the Iowa State Fairgrounds, site of one of Mitt Romney’s more ignominious moments, to rally Democratic supporters in a key swing state.

At the campaign rally in Des Moines, Obama is expected to keep up attacks on the presumptive Republican nominee’s experience as the head of Bain Capital, a private equity firm, as the president seeks to paint Romney as out of touch with the middle class.

Last August, during the Iowa State Fair, Romney famously remarked during a contentious exchange with local residents that “corporations are people,” a comment that has haunted him as the former Massachusetts governor attempts to sell his economic message to independent voters.

On Thursday, the Obama campaign distributed a new video clip featuring Romney’s appearance in Des Moines.

Though Republicans, and some Democrats, have recoiled at Obama’s attacks on Romney’s private equity experience, the president and his reelection team have doubled down.

At several campaign fundraising events in Colorado and California on Wednesday, Obama hit Romney repeatedly, saying he should be proud of his private sector success but saying the lessons Romney learned as a corporate raider leave him ill prepared to boost the American economy.

“He seems to believe that if CEOs and wealthy investors like him are getting rich that the rest of us automatically do, too,” Obama told a crowd of supporters at the Fox Theatre in Redwood City, Calif. “Now, we believe in the free market. We believe in risk-taking and innovation. This whole area is built on risk-taking and innovation. But we also understand that it doesn’t happen in a vacuum. It happens because of outstanding schools and universities. It happens because of a well-regulated financial market. It happens because we have extraordinary infrastructure. It happens for a whole host of reasons. But Governor Romney doesn’t seem to understand that.”

Obama’s stop in Des Moines will come after he tours a wind turbine manufacturing facility in Newton, Iowa, in his latest effort to push Congress to support his five-point to-do list of economic initiatives.

At TPI Composites, Obama will call on Capitol Hill lawmakers to support an extension of a clean energy tax credit. Without the credits, the industry could lose up to 37,000 jobs over the coming year, administration officials said.

The tax credit for wind projects was extended three years as part of Obama’s stimulus bill in 2009, but it is set to expire at the end of the year. The proposed extension is among five economic initiatives on the “to-do list” Obama has challenged Republican lawmakers to support in an increasingly partisan election year.

White House officials said they are hopeful that Congress will support the wind proposal, which has bipartisan support. In March, Sen. Chuck Grassley (R-Iowa) was among a group of senators that called for a two-year extension of the tax credit.

But in a statement, Grassley criticized Obama for stumping for the plan in his home state rather than talk with Congressional leaders directly.

“The president could exert his leadership by working with Congress on a way forward instead of calling for a provision that’s a no-brainer for many of us,” Grassley said. “He’s focusing on the easy part of a bigger task. The stakes for the wind industry and the country in general will only get worse with delay. It’s time to act, not politick.”

Obama chose to appear at TPI Composites, which underwent a major downsizing six years ago, because the company used the tax credit to help build a new facility in Newton and now employs 700 workers, officials said.

Heather Zichal, Obama’s deputy assistant for energy, said that the initiative supports “real jobs. . .in communities across the country whether it’s in the development or manufacturing side, and we need to continue to support this industry because it’s at a pivotal time.”