Sen. Rob Portman, R-Ohio, is resuming his role this cycle as faux-Barack Obama, pretending to be the president during debate prep with Republican rival Mitt Romney. It's a task Portman tackled in 2008 as well, but according to GQ's Robert Draper, Portman wasn't the McCain team's first pick the last time around. "[Republican debate prep mastermind Brett] O'Donnell initially wanted McCain to practice against a black man: former RNC chairman Michael Steele, who turned out to be, in the words of one McCain adviser, 'a disaster,' " wrote Draper.

With Portman in and Steele out, Portman "excelled as Obama," but it was the debate format, a town-hall style, that may have doomed McCain. "McCain said, 'I'll thrive at this.' Then he walks onstage, and it's dead quiet. People aren't asking him goofy questions, no guy's wearing a shark costume -- all the carnival atmosphere he loves is instead replaced by this dead, eerie climate, almost like you're in that in-between land between heaven and hell," a McCain adviser told GQ.

During the Democratic primaries of that cycle, then-Sen. Obama was disinterested in the debates, until John Edwards snapped him to attention in October 2007 in Philadelphia. "Focus, Barack," Edwards snapped during a break. "You've got to focus!" GQ reports Edwards as saying. The gesture seemed to work, as Obama immediately went after Hillary Clinton. In the piece, that anecdote served as a reminder that even though Obama is known for his soaring rhetoric, the experts haven't always been impressed with his debate performances.

The same goes for Romney, who let McCain get the best of him during the 2008 GOP primaries, ("We disagree on a lot of issues, but I agree: You are the candidate of change," McCain zinged then) but showed improvement during the 2012 round.

"What's clear is this: When the feed goes live, both men will be as assiduously trained and groomed as two spaniels at Westminster," Draper wrote, of the presidential debates that start next week. "But the leashes will come off, and for 90 minutes Barack Obama and Mitt Romney will perform an American tradition that has historically not brought out their best."