As they enter the final rounds of their heavyweight bout for the Democratic nomination, will Sens. Barack Obama and Hillary Clinton be on their best behavior or will they sharpen their jabs at tonight's debate?
The duel between the last two Democratic candidates has gotten more fiery in recent weeks, with heated debates over topics ranging from Tony Rezko to President Reagan, civil rights history to Pakistan and with visual showdowns featuring cold stares and the infamous "snub" after the State of the Union address.
Despite their stated intentions to take the high road, both Clinton and Obama have attacked each other with a passion. The items correcting their opponent's claims on the fact-check sections of their respective Web sites tripled in January compared with the previous month.
At their last debate before Super Tuesday, both candidates will want to make a strong impression without turning off voters, say pundits.
"The tension between the two camps has been escalating and so much of this race hinges on what happens in four days, I would be surprised if it didn't continue to be fairly contentious," said Robert Oldendick, a political science professor at the University of South Carolina.
"They're very similar on the issues and so with those distinctions blurred, it comes down to personality. When it comes down to that, you have to ratchet up the rhetoric to make an impression."
Others expect both candidates to be on their best behavior.
"There's going to be an enormous outburst of civility," said Mitchell Moss, a professor of urban policy and planning at NYU.
"It's been a good old-fashioned family fight and no one wants to raise the temperature any higher. This will be an intense battle, but they're not going to do it in front of the cameras."
And don't expect a repeat of the snub, when Obama turned his back on Clinton while she reached out to shake the hand of Sen. Ted Kennedy, D-Mass., Monday night after the State of the Union, says Molly Epstein, a professor of management communications at Emory University who has studied body language in political campaigns.
"Obama will be extremely sensitive to everything he does, where he rests his eyes, who he turns to," she says.
"It will be in both of their interests to behave in a way that is presidential, looking the other person in the eye no matter how you feel about them."
These nonverbal cues will be a vital part of tonight's debate because most viewers have heard the speeches before.
"We're unlikely to hear any words that we haven't heard before," says Epstein. "We've heard it all at this point so viewers will be looking at facial expressions and body positions to subtle actions like the twitch of an eye like they never have before. Studies show that 98 percent of persuasion is based on what we see, not what we hear."
The clearest recent example of such non-verbal cues was the series of photographs depicting Clinton and Obama after the State of the Union.
While political junkies and pundits analyzed photos of the incident as intently as the Zapruder film, questions remain about Obama's true intentions, Clinton's sensitivity and the media's obsessions.