U.S. presidential candidates Barack Obama and John McCain clashed on on how to lead the country out of economic downturn in their second round of debate Tuesday night at Belmont University in Nashville, Tenn.

　　Democrat Obama said the country is in the worst financial crisis since the Great Depression as he began his second presidential debate with Sen. John McCain.

　　He blamed President George W. Bush and McCain, both Republicans, for the crisis, saying they had worked to "strip away regulation."

　　McCain proposed having the government buy up and renegotiate bad home loans to stabilize the property market.

　　He admitted the plan would be expensive but said it was necessary.

　　In response to a question from moderator Tom Brokaw, McCain floated the names of billionaire investor Warren Buffett -- an Obama supporter -- and Meg Whitman, the former eBay executive who is one of his economic advisers.

　　Obama agreed that "Warren would be a pretty good choice," but declined to go into specifics about who he would nominate.