McCain repeated the two major negative talking points of his campaign this week, calling on Obama to explain his relationships to 1960s radical Bill Ayers and the Association of Community Organizations for Reform Now (ACORN), a community group that has been accused of fraudulently registering voters.
"[Sen. Hillary] Clinton said in her [Democratic primary] debates with you [that] we need to know the full extent of your relationship [with Ayers and] with ACORN," McCain said. "All of these things need to be examined, of course."
"I'll respond to these two allegations," Obama said. "Mr. Ayers has become the centerpiece of McCain's campaign. Let's get the record straight. Ayers is a professor of education in Chicago. Forty years ago, when I was 8 years old, he engaged in despicable acts. I have roundly condemned those acts."
Obama said he served on a board with Ayers along with a former ambassador and the presidents of the University of Illinois and Northwestern University.
McCain accused Obama of lying about his willingness to take public spending and said Obama should have done more to repudiate Rep. John Lewis, D-Ga., an Obama supporter who compared campaign rallies for McCain and his running mate, Alaska Gov. Sarah Palin, to those of segregationist Alabama Gov. George Wallace.
"Congressman John Lewis said Palin and I were associated with segregation, deaths of children in church bombings," McCain said. "That to me was so hurtful. And Obama, you didn't repudiate those remarks. Whenever there have been out-of-bounds remarks from Republicans, I'd repudiate [them]."
Obama said Lewis was responding to racist and threatening language heard at McCain-Palin rallies in response to the mention of Obama's name, which the Republican candidates did little to stop.
"Lewis, he -- unprompted, without my campaign's awareness -- said he was troubled with what he was hearing at some of the rallies your running mate was holding," Obama said. "Shouting things like 'terrorist' and 'kill him' that your running mate didn't stop or mention. I think Lewis' point was that we have to be careful with how we deal with our supporters."
Trailing in the polls by as much as 14 points and facing deficits in numerous battleground states, according to a New York Times/CBS News poll, McCain is caught between giving his base what they want and going negative or responding to polls that indicate Americans are fed up with the tone of the election.
Both an ABC News/Washington Post and the New York Times/CBS News polls found that a spate of McCain attacks on Obama actually hurt McCain instead of Obama, because voters objected to his negative tactics.
Obama argued that McCain has relied more heavily on attacks than he has.
"I think we expect campaigns to be tough," Obama said. "If you look at the record ... two-thirds of the American people think McCain is running a negative campaign. One hundred percent of your ads have been negative."
"Not true," replied McCain.
"It's absolutely true," Obama shot back.