Part of what makes election debates so important can be attributed to way images and impressions shape a campaign.
"Style has outweighed substance in all of the presidential debates, going all the way back to 1960," says Alan Schroeder, author of "Televised Presidential Debates: 40 Years of High-Risk TV."
First televised debate: 1960, Nixon vs. Kennedy
The debate setting usually favors the more media savvy, camera-friendly candidates.
"John Kennedy was a dashing, very cool-looking guy. It was the era of cool," recalls NBC’s Tom Brokaw. "He had a new cut of a suit on. We had been used to Richard Nixon, Dwight Eisenhower and other people like Bob Taft as our national political figures. Suddenly, here was this romantic, almost prince-like man. There was something just utterly charismatic about him, however you felt about his politics… Before we even used the phrase 'rock star,' he was a rock star."
Kennedy’s tanned appearance and even skin tone on-camera couldn’t have hurt. Chris Matthews recalls hearing a story from television veteran Bill Wilson: "People thought nobody had makeup that night. Even though Kennedy had the great tan from Florida, he went out and put makeup on," Matthews says. Nixon didn’t. He also had just gotten out of the hospital a few days before the debate, where had a temperature of 102. On debate night, he looked sallow.
Nixon had also banged his knee on the cab door as he traveled to the studio. "If you look at the old tapes, you can see Nixon sort of going back and forth on one leg to another [on stage]," recalls Matthews. "So the Kennedy crowd gamed him, to some extent, by making sure that they had to stand up during the debate."
Nixon’s shifting his weight, it is widely-believed, added to the impression of a lack of confidence.
"The urban legend now is that people who heard it on radio thought that Nixon had won, but people who watched it on television thought that John F. Kennedy had won," adds Brokaw.
It’s in the details
George H.W. Bush, in 1992, looked like an uncomfortable old general, while Bill Clinton looked young, at ease, and in his element. Clinton had rehearsed ahead of time with a replica of the stage layout and even figured out how to move on stage.
George H.W. Bush was also caught on-camera in the background checking his watch and appearing disinterested. This made him looked bored, and Clinton like he wanted the job.
"If George Bush had been seen as having won against Bill Clinton in that debate, and if he won the election, would we have focused on the watch check?" asks Chris Matthews.
Debate 2004
George W. Bush and John Kerry’s debate styles are worlds apart.
"George Bush is much more able to articulate his message decisively and to the point, observes Shroeder. "Kerry has a lot of difficulty boiling messages down. He’s not a story-teller, and that’s one of the things that seem to work pretty well in debates," he adds.
But Schroeder gives Kerry high marks on preparation—and knowledge. "He’s in total command of the issues. And Kerry has a record of really rising to the occasion."
Pres. Bush, like all incumbents, will have to defend his record. "Bush’s record has been controversial, and he hasn’t been challenged on it a lot in a face-to-face setting like this."
Long negotiations set up the debate rules this year. The chairs will be equal height, the candidates can take notes, and the room temperature was even one of the negotiating points.
According to Schroeder, everything will be tested and scrutinized— including the color of the suits and the ties.
"I think I can foresee, when 'Saturday Night Live' or 'The Daily Show with Jon Stewart' do a mock debate, you’ll have the referee going over and looking at the instant replay and seeing whether they played by the rules or not," imagines Brokaw.
The future, after all, is at stake. "Not just the immediate future, like, 'Do I get the presidency or not?' but the historical judgment that will be rendered on them is largely determined by how they perform at debates," says Schroeder.
MSNBC's Chris Jansing contributed to this report.