Biden hits road to defend Obama's economic record

"We're are about protecting the public sector, they are about protecting the privileged sector," Biden said. "We’re a fair shot, and a fair shake. They’re about no rules, no risk. And no accountability."

The vice president warned that electing a GOP hopeful would reverse the economic recovery.

"I want to tell you what's real bankruptcy. The economic policies of Gingrich, Santorum & Romney," Biden said. "If you give any one of these guys the keys to the White House, they will bankrupt the middle class again."

Biden landed particularly tough jabs against GOP frontrunner Mitt Romney, noting "Bain Capital wasn't lining up" to save the auto industry.

Most voters list the economy as their No. 1 concern going into the November general election. Mitt Romney, the GOP front-runner, has repeatedly attacked Obama's policies and touted his own business experience.

But Biden credited the president with advocating for the auto bailout

"The president didn’t flinch. This is a man with steel in his spine," Biden said. "He knew rescuing the industry wasn’t popular. He knew he was taking a chance.

"He said, we are not going to give up on a million jobs, and the iconic industry America invented. Not without a fight."

This article was updated at 11:53 a.m.