As much as the pundits are talking about how Obama is going to have to be more agressive against Romney to get momentum back on his side, I don't think that's possible. He had no answer prior and has no answer now to problems in his record. Problems that the media has ignored for Obama's benefit. In the first debate, he didn't even answer a lot of criticism, no doubt because he can't defend his record and doesn't want to bring any more attention to it by trying. In this sense, there is no way he can win any debate. He says one thing, but does another. He failed the American people. And they know it.
The other aspect that hurts Obama in a debate is that people watching the debate see Romney as he really is and not as Obama and the liberal media say he is. People like Romney. They're impressed with Romney. Seeing Romney in person is necessarily a bad thing for Obama during debates because the comparison between the Romney the liberals created and the real Romney is stark. And unnecessary - they didn't have to go lie about him, but they did! They show their true colors, hurting liberals in an election year once again.