If history is any guide, Wednesday's debate between President Obama and Republican Mitt Romney will attract a huge number of viewers -- maybe more than the 52 million who tuned into the first debate in 2008 between Obama and Republican Sen. John McCain (R-Ariz.). How those viewers ultimately judge the results, however, depends on whether they're relying on their eyes, their ears or pundits and the polls.
Debates give voters their only opportunity to make a side-by-side comparison of the candidates, so the difference in how they comport themselves can make a big difference. Much has been made of Richard Nixon's haggard and sweaty appearance in his first debate against John F. Kennedy in 1960; despite Nixon's solid performance at the microphone, most people who watched the event on TV thought Kennedy came out on top in large part because he appeared more in command. Al Gore similarly undermined his performance in his first debate against George W. Bush by repeatedly sighing and rolling his eyes in response to Bush's comments.
But comportment is just part of the equation for voters. The debates also air the candidates' differences over policy, albeit with a minimal amount of detail.
Thomas E. Patterson, a professor at Harvard's John F. Kennedy School of Government, said these discussions mainly help the candidates appeal to their own parties. For example, Patterson said, "When Romney starts talking about excessive taxation and the ability to get the economy going, that’s going to be music to the ears of those Republicans out there." And when Obama says the economy isn't great but we're making progress, Patterson said, that's going to resonate with Democrats.