President Obama, speaking at the NATO Summit in Chicago on Monday, questioned whether Mitt Romney's business experience at Bain Capital made him fit to be president in some of the most stark terms to date.

The president answered a reporter's question about Newark, N.J. Mayor Cory Booker's comments, which he has since walked-back, that attacks on Bain Capital were "nauseating." The comment by the high-profile Democrat has dominated the news cycle since Sunday.

"First of all, I think Cory Booker is an outstanding mayor. He's doing a great job in Newark and helping to turn that city around." Turning to Bain, he said, "I think it's important to recognize that this issue is not a, quote, distraction -- this is part of the debate that we're going to be having in this election campaign about how do we create an economy that everybody, top to bottom, folks on Wall Street and folks on Main Street, have a chance at success."

Obama then took on Romney directly. "You know, he's not going out there touting his experience in Massachusetts. He's saying, I'm a business guy and I know how to fix it, and this is his business," he said. "When you're president, as opposed to the head of a private equity firm, your job is not simply to maximize profits," he said.

UPDATE: Mitt Romney responded to Obama's charge on Monday. "President Obama confirmed today that he will continue his attacks on the free enterprise system, which Mayor Booker and other leading Democrats have spoken out against," he said in a statement. "What this election is about is the 23 million Americans who are still struggling to find work and the millions who have lost their homes and have fallen into poverty. President Obama refuses to accept moral responsibility for his failed policies. My campaign is offering a positive agenda to help America get back to work."