Mr. Obama, meanwhile, must work to keep in check his attitude so that he doesn't lose his advantage of appearing as a more "likable" candidate.

"Obama is an experienced debater but an inconsistent performer who is years out of practice, capable of projecting a calm, commanding image -- or appearing bored, testy or condescending enough to snark out the unforgettable 'You're likeable enough, Hillary' crack four years ago," Politico's Glenn Thrush writes. "The debates didn't sink him in 2008 -- they were probably a net plus taken as a whole, his staffers believe -- but this time around Obama's bedrock political asset is his likeability and capacity to bond with middle-class voters. Hence the unwritten rule in debate prep sessions against Sen. John Kerry, Romney's stand-in: Hold your ground, but no more sneers."

While both sides are already working to set expectations for the debate, it's unclear how much influence it can really have on the state of the race. In the Politico poll, 46 percent say they will definitely vote to re-elect Mr. Obama, 42 percent say firmly they are voting for Romney, and just 9 percent may consider changing their minds.

"We've never had a debate where the electorate was this polarized," Democratic pollster Celinda Lake told Politico. "There's a real question about how many voters are left to move in the debate."

The New York Times, meanwhile, notes, "History shows that candidates have different ways to score through presidential debates: the forceful put-down, the surprising show of skill, the opponent's fumble, superior post-debate tactics. But it also shows that to fundamentally alter the direction of a campaign, a candidate usually has to accomplish all of those things."

The first presidential debate will be shown on KTVA CBS 11 News at 5 p.m. on Wednesday, October 3.