Sen. John McCain acknowledged he is trailing Sen. Barack Obama in the 2008 presidential race, but says he long ago got used to being an "underdog" and willl keep fighting because he insists the Democratic nominee has neither the experience nor the candor to win the White House.
"This is a tough campaign," McCain told ABC News' Charlie Gibson in an exclusive interview. "I'm the underdog. I've always been the underdog from the beginning."
And in a surprising tactic, McCain repeatedly invoked Democratic Sen. Hillary Clinton -- an unpopular figure among conservative Republicans -- while defending his campaign's most controversial strategies: spending $300 billion to buy up peoples' mortgages and linking Obama to 1960s anti-war radical William Ayers.
McCain was most heated when pressing his campaign's attempts to connect Obama to Ayers, a co-founder of the Weather Underground, a Vietnam-era group that executed domestic bombings and plotted attacks on the U.S. Capitol and the Pentagon.
"[Ayers] wasn't a guy in the neighborhood. [Obama] launched his political career in his living room, in Mr. Ayers' living room. And I don't care about two washed-up old terrorists that are unrepentant about trying to destroy America. But I do care, and Americans should care, about his relationship with him and whether he's being truthful and candid about it," McCain said.
Obama says the personal attacks levied against him by the McCain campaign, particularly references to Ayers, are an attempt to "score cheap political points."
"Why don't we just clear it up right now," Obama told "World News" anchor Gibson in an exclusive interview on Wednesday. "I'll repeat again what I've said many times. This is a guy who engaged in some despicable acts 40 years ago when I was eight years old. By the time I met him, 10 or 15 years ago, he was a college professor of education at the University of Illinois . . . And the notion that somehow he has been involved in my campaign, that he is an adviser of mine, that . . . I've 'palled around with a terrorist', all these statements are made simply to try to score cheap political points."
But McCain was unrepentant when asked on Thursday by Gibson if Ayers is a "critical issue or factor in this campaign."
"I think it's a factor about Senator Obama's candor and truthfulness with the American people," McCain replied, before adding, "I don't care about Mr. Ayers, who on Sept. 11, 2001, said he wished he'd have bombed more. I don't care about that. I care about [Obama] being truthful about his relationship with him. And Americans will care."
Obama said on Wednesday to ABC News that the McCain campaign is making personal attacks "the centerpiece of the discussion in the closing weeks of a campaign where we are facing the worst economic crisis since the Great Depression and we're in the middle of two wars."
"I think that makes very little sense, not just to me but to the American people," Obama said.
McCain demurred when asked whether Obama's character or lack of candor disqualifies him to be president.
"I'll leave that up to the American people. But I have every right to insist that he be candid and truthful with the American people. And he needs to be asked about it, and he needs to be forthcoming," McCain said.