run the campaign as a content-free political science experiment, intent on proving that a challenging candidate doesn't need to offer anything and can instead rely on a weak economy to unseat the cinumbent. Of course, today the economy is slightly on the mend and doing fairly well in swing states.
Nate Silver points out that the first debate typically improves the standing of the challenging party in the polls. This makes sense, since the electorate has generally seen & heard more about what the incumbent has done and will do, and Presidential candidates are generally convincing people. So we will probably see some tightening in the polls, both nationally and in swing states. At the moment, Obama is in a strong position, but Silver's odds give the Romney campaign a roughly one-in-five or one-in-six chance of changing the dynamics of the election enough to win. That probably means pushing bringing Ohio (and possibly Wisconsin, but let's not get too greedy) back into competitive territory, while also pushing Nevada, Iowa, and Colorado into 50-50 territory. Considering that all three of those states have given a Obama a persistent edge, Mitt Romney has his work cut out for him.