"I would order the secretary of the Treasury to immediately buy up the bad home loan mortgages in America and renegotiate at the new value of those homes, at the diminished value of those homes, and let people be able to make those payments and stay in their homes," he said.

"Is it expensive? Yes. But we all know, my friends, until we stabilize home values in America, we're never going to start turning around and creating jobs and fixing our economy, and we've got to give some trust and confidence back to America."

McCain also said it was important to reform the giant benefit programs such as Medicare, Medicaid and Social Security.

"My friends, we are not going to be able to provide the same benefit for present-day workers that present-day retirees have today," he said, although he did not elaborate.

The two men also competed to demonstrate their qualifications as reformers at a time voters are clamoring for change.

McCain accused Obama of being the Senate's second-highest recipient of donations from individuals at Fannie Mae and Freddie Mac, the two now-disgraced mortgage industry giants.

"There were some of us who stood up against it," McCain said of the lead-up to the financial crisis. "There were others who took a hike."

Obama shot back that McCain's campaign manager, Rick Davis, has a stake in a Washington lobbying firm that received thousands of dollars a month from Freddie Mac until recently.

Pivoting quickly to show his concern with members of the audience listening from a few feet away, he said, "You're not interested in politicians pointing fingers. What you're interested in is trying to figure out, how is this going to impact you."

But that didn't stop the two men from criticizing one another repeatedly as the topics turned to energy, spending, taxes and health care.

Obama said McCain was going to require taxes on the health benefits workers receive from their employers at the same time his plan would wipe out the ability of states to enforce their own regulations to require tests such as mammograms.

McCain countered that under his rival's plan "Sen. Obama will fine you" if parents fail to obtain coverage for their children but had yet to say what the fine would be. "Perhaps we will find that out tonight," he said.

Obama quickly followed up, saying that McCain "voted against the expansion" of the children's health care program the government runs.

The two men prefer dramatically different approaches to easing the problem of millions of uninsured Americans. McCain favors a $5,000 tax credit that he says would allow families to find and afford health care on their own.