Obama has received $126,349 ($120,349 from employees and $6,000 from Political Action Committees, or PACs) since he joined the Senate in 2005, according to the Center for Responsive Politics.
His total is the second-largest of any member of Congress, right behind Sen. Chris Dodd, D-Conn., at $165,400.
McCain has received $21,550 from employees (nothing from PACs) since 1989 -- a period 14 years longer than Obama has been in the Senate -- again according to the Center for Responsive Politics.
Obama said he was the real reformer of the two, who had called on Treasury Secretary Henry Paulson and Federal Reserve Chairman Ben Bernanke to take action while McCain was waiting for the free market to correct itself.
"I've got to correct Sen. McCain's history, not surprisingly. Deregulation of the financial system ... Sen. McCain, as recently as March, bragged about the fact that he's a deregulator. Two years ago I said there was a subprime crisis we had to deal with. I wrote to Paulson and Bernanke and told them it's something we need to deal with. I never promoted Fannie Mae."
Then Obama switched tacks, speaking directly to Oliver Clark, the audience member who had asked a question about the bailout, saying, "You're not interested in politicians pointing fingers. You're interested in the impact on you. This is not the end, this is the beginning of the process."
Asked if that meant he believed the economy was poised to get much worse, Obama said, "I am confident about the American economy, but we are going to have to have to leadership from Washington."
The two men clashed over whether the United States military should make cross-border excursions into Pakistan to fight suspected militants, offering different perspectives on how the United States should flex its might and turning the issue into a question of leadership.
McCain accused Obama of pandering and emboldening American enemies by announcing the military strikes he would take in advance.
"I'm not going to telegraph my punches, which is what Sen. Obama did," said McCain, adding that he follows the lead of his hero Teddy Roosevelt, who said the United States should "talk softly but carry a big stick."
In that heated exchange, Obama accused McCain of hypocrisy.
"This is a guy who sang 'bomb, bomb, bomb Iran,' who called for the annihilation of North Korea -- that I don't think is an example of speaking softly."
McCain said Obama "was wrong about Iraq and the surge. He was wrong about Russia when they committed aggression against Georgia. And in his short career he does not understand our national security challenges. We don't have time for on-the-job training."
Both men conceded that the nation's energy policy needed to be changed but disagreed on how best to end American reliance on foreign oil.
"I've disagreed strongly with the Bush administration on this issue. I've traveled all over the world to look at greenhouse gas emissions," said McCain.
"What's the best way of fixing it? Nuclear power. I was on Navy ships that had nuclear power plants. Nuclear power is safe and clean. I know that we can reprocess the spent nuclear fuel. The Japanese, British and French do it. Obama opposes that."
Obama said McCain had voted 23 out of 26 times against alternative fuel bills presented to the Congress and said he supported nuclear power, in addition to solar, wind and thermal energy.