"Romney's strengths are experience and preparedness. He has spent a lot of time preparing for these debates, by all accounts, over the course of the summer. And he's had a lot of experience over the last four years participating in these debates," said Schmidt. "When you watch the arc of his progress - from 2008 to 2012 - it's clear he has the capacity for improvement and he gets better. Obama simply hasn't participated in the number of debates that Romney has, and he hasn't, by all accounts, spent the time preparing that Mitt Romney has."

Nevertheless, Simmons argues that despite expectations and his proclivity for long-winded answers, the president's biggest responsibility tonight is "to not drop the ball in any significant way."

"A tie is perfectly fine for the president," he said. "The pressure is clearly on Governor Romney to change the dynamic. The president needs to do no harm."

At this point, there's only so much either candidate can do to prepare. But according to Simmons, there are a few last-minute nuggets of advice that apply to all debaters - Republican or Democrat.

"Wear good makeup. Don't sigh. Don't look at your watch," he said. "Those things are probably point number one."