During the primaries, Mitt Romney participated in almost two dozen debates with his opponents, and won most of them. By that I mean that among those on the stage, he usually seemed like the one who was neither completely bonkers nor a blithering idiot. At least in the context of the 60-second answers candidates were usually allowed, he was reasonably well-informed and had a well-prepared answer to most of the questions he was asked.

But although he was often the main focus of discussion as one candidate after another tried to take him down, Romney was still only one of many candidates who got a chance to talk. If you added up all the time he spent speaking in each debate, it probably would have come out to about 15 minutes at most. But in the debates that start next week (the first one is Wednesday), it will just be Barack and Mitt. Each of the three presidential and one vice-presidential debates will be 90 minutes long, meaning Americans will get to watch Romney talk for just under 45 minutes, far and away the longest exposure they’ve ever had to him. Up until now, Americans’ exposure to Romney has come in tiny little chunks-an 8-second sound bite here, a 30-second ad there.

How is he going to wear on them? It’s hard to tell. Voters have already seen plenty of Barack Obama, and what they get of him is likely to be what they’ve gotten used to for the past four years. He’ll probably be relaxed most of the time, perhaps halting now and again, mostly thoughtful, maybe a little boring. He’ll make some very good arguments, and a few that ramble around where they could have been more direct. If a significant number of voters changes their opinion of Obama based on what happens in the debates, it will absolutely stunning.

Romney, on the other hand, will be under tremendous pressure to both show voters he ought to be president, and come up with something dramatic. And dramatic moments almost never involve you looking great; instead, they usually involve making your opponent look terrible. About the only exception I can think of was in 1984, when Ronald Reagan responded to a question about his advancing age (he was 73 at the time and possibly showing the early signs of the Alzheimer’s that would later take his life) by saying, “I will not make age an issue in this campaign. I am not going to exploit for political purposes my opponent’s youth and inexperience.” Everyone laughed, and the nation’s press corps agreed never to speak of the topic again.

But as I say, that was the exception-almost every one of those “decisive moments” with which the press becomes consumed in the days after the debate involves a screw-up of one kind or another. I’m sure the Romney debate prep team is trying to come up with something Romney can say that would make Obama look really, really bad. But it’s hard to imagine what it might be.