A Minnesota labor activist is in the middle of an Obama campaign ad released Monday attacking Mitt Romney's record at Bain Capital, the private equity firm that's become the nexus of an election-year debate over the nature of American capitalism. David Foster was the lead negotiator for the steelworkers at GST Steel, a troubled Kansas City firm that was loaded up with debt, cashed out, and bankrupted after Bain Capital took it over. Speaking alongside longtime steelworkers who saw their pensions and health insurance decimated, Foster rates the episode as one of "the most painful experiences of my life." The Obama campaign has long been expected to make an issue of the people who lost their jobs during some of the Bain acquisitions, and this ad campaign appears to be the start. A two-minute version is going up in Iowa, Colorado, Pennsylvania, Virginia and Ohio. There's also a six-minute video on a new Web site called RomneyEconomics.com.