Barbara at Mahablog has some positive thoughts about tonight's debate:

Awhile back I wrote about this article in the July/August Atlantic Monthly, by James Fallows (who has done some great work this year), on Bush's and Kerry's debate style. Kevin Drum writes about it today. Time for a review.
 
Bush has been a remarkably successful debater in the past. He finessed Ann Richards articulately. His success against Gore is harder to analyze -- part Gore being overbearing, part post-debate spin. Bush was just impressive enough to persuade nearly half the electorate to vote for him..
 
Can he pull it off again?
 
Of course he might, but I think it's going to be a lot harder for him now. This is true in spite of the fact that if Bush manages to stand up straight and appear self-assured, no matter what he or John Kerry say, he'll be declared the "winner."
 
As Fallows indicates, Bush seems to be experiencing some kind of mental deterioration. He's gotten worse since 2000. And his fuse seems to have gotten shorter. If he loses his temper, or his focus, tomorrow night, especially while standing next to a cool, articulate Kerry, Bush's campaign would take a serious blow.
 
And what's he going to talk about? His stump speech, I'm told, consists of a stand-up act making fun of Kerry combined with happy talk about Iraq. If he tries the Kerry jokes tomorrow he'll look like an asshole (which he is), and I'm sure Kerry is ready to pounce with the facts about the increase in violence in Iraq, plus Colin Powell's recent glum assessment.
 
Still, we know that Kerry's performance will be picked apart and Bush's will be inflated into a victory, no matter what they do. Bush will be declared the "winner" if he stays on his feet and doesn't pick his nose on camera. When it's over, you'll be able to flip around the dial and watch Pat Buchanan declare that Kerry "didn't lay a glove on him," while the symbiot George Will/Peggy Noonan says, "Doesn't [Bush] look presidential?"
 
But if he loses his temper ...  well, we can hope.