Obama comments came after a reference to a 2008 op-ed in the New York Times Romney wrote that was titled "Let Detroit Go Bankrupt," which has been a standard feature of his stump speeches.
During a separate appearance on behalf of Obama in Parma, Ohio, Clinton also joined the auto bailout fray.
"We are growing manufacturing jobs … and there is no more clear example of this than what happened in the automobile restructure," he said. "And I don't like it when it's called a bailout because it's not fair. No banks would finance this, so the government came in and helped with loans and an investment in stock of General Motors and Chrysler.
"It's important to remember that one in eight jobs in Ohio are tied to automobiles, and [Obama] saved those jobs," Clinton continued. "A million of them. And now 250,000 more people are working in the automobile industry than there were the day the automobile plan was signed."
In his debate with Obama on Tuesday, Romney accused Obama of misrepresenting his position on the auto bailouts.
"I know he keeps saying, 'you want to take Detroit bankrupt.' Well, the president took Detroit bankrupt,” Romney said. “You took General Motors bankrupt. You took Chrysler bankrupt. So when you say that I wanted to take the auto industry bankrupt, you actually did.”
Democrats have argued, as Clinton did Thursday, that Romney was wrong because private sector assistance for the auto companies was not available during the economic panic of 2008.
The auto bailouts were first initiated under former President George W. Bush, but Obama has turned them into a major feature of his campaign for reelection, especially in Midwestern states like Ohio.