Can McCain Pull Off October Surprise?

"Regan nailed it in those debates. Like this year, there was a sense that people were clearly dissatisfied by the status quo, but they were not yet convinced that Reagan was the answer. They needed to be convinced, and he did it in the debate. Reagan and Carter went from being essentially tied to Reagan winning by 10 points."

Perhaps the most iconic October surprise came neither in October, nor as a surprise. In the 1988 election between then-Republican Vice President George H. W. Bush and Mass. Gov. Michael Dukakis, Bush ran an ad depicting Willy Horton, a convicted felon sentenced to life, who committed rape and robbery while on a state-implemented weekend furlough in Massachusetts.

Though the connection between Dukakis and Horton was made in the primaries, Bush did not effectively use the information until his campaign put out a television ad called "Weekend Passes" on Sept. 21, 1988, that used Horton's image.

"There is something reminiscent in making that connection to an undesirable," said Clarke about the McCain strategy to connect Obama with Ayers.

"I'm betting [McCain] will try to do more of that. He'll keep raising issues and doubts about Obama's character and associates, including at the debate," she said.

"If it were anybody else but John McCain, I'd say this election is over. But time and again, he has proved his critics wrong. If anyone can pull this off, it is him."

And that might be the biggest surprise of all.