8 Questions About the Debates

Of course, the second debate this fall, between the running mates, could be among the most closely watched, given the interest in Alaska Gov. Sarah Palin's candidacy. But no matter how she does, Dan Quayle proved that a vice presidential candidate can have a lousy night without any political consequence.

Who has more to gain or lose?

4. In a race that has been so competitive for so long, neither candidate can afford a misstep.

The pressure is certainly on Obama. He has not comfortably crossed the threshold of acceptability with enough voters. Questions about his experience, his readiness to be commander in chief and his background remain obstacles in his path. But the political climate favors Democrats over Republicans this fall: If Obama can use the debates to deal with the doubts about his candidacy, he could emerge as a clear favorite to win.

"The 'Is he ready?' question still hovers over the campaign," said Republican pollster Whit Ayres. "If he shows the answer is 'yes,' then it really helps him. If not, then it's President McCain."

That assumes McCain breezes through these debates. But there are several obstacles for him, as well. One is that the issue agenda, as Republican strategist Tom Rath put it, "has turned away from his sweet spot" of national security and toward the economy. Another is that he has to escape being seen as an extension of the Bush years.

Who has been the better debater?

5. Obama is well known for his rhetorical skills and is an orator of clear gifts who can lift audiences with his words. McCain is well known as a master of the town meeting, where his quips, straightforward exchanges and interaction have won him plaudits.

But when it comes to debating, neither has been a natural. In the primaries, Obama struggled at first. By his own admission, he had trouble mastering the format of quick answers and sharp ripostes. Eventually, he started to get better.

Howard Wolfson, who was Sen. Hillary Rodham Clinton's campaign communications director, replied when asked who was better: "Obama -- 22 debates was very good practice."

McCain was less predictable as a debater. Sometimes he was unfocused, but when it mattered most, he scored well. His advisers believe his performance in a New Hampshire debate in September 2007, when he was being written off, helped put him back into the fight for the GOP nomination.

As one Democratic strategist put it: "It came as no surprise that both campaigns wanted the looser rules we have this go-around. Time constraints hamper both men because one tends to be professorial in his replies while the other rambling. People who follow politics closely know that this forum is not ideal for either."

Still, neither would have gotten to this moment without having navigated the longest series of primary debates in the history of presidential politics. "Both held their own against skilled opponents," said Rick Sloan of the International Association of Machinists. "Both found ways to convey their core messages and yet reinforce the strengths of their personalities."

What is each candidate's biggest vulnerability, and how can he deal with it?

6. Substantively, Obama is seen as weaker on foreign policy and national security, although his advisers are eager to have a debate on these topics because they believe he is underestimated. McCain is viewed as weaker on economic issues, but by jumping into the middle of the negotiations in Washington over the financial rescue package he hoped to show voters he can lead on that topic.