I think Republicans, at least the ones I run into, are wildly overoptimistic about the debate tonight.
Yes, Harris isn’t any good at this, but she will be prepared for nearly every eventuality and will have rehearsed every line. I’m guessing her debate prep has had the goal of ensuring that she doesn’t have to react spontaneously to any single thing that happens tonight. I wouldn’t be shocked, then, if she clears the bar of adequacy the way she did in the CNN interview — not impressive, but not obviously terrible, either.
As for Trump, Biden’s collapse in the first debate obscured the fact that he wasn’t very good. In fact, after his historically bad opening ten minutes, Biden held his own at times. So, Trump has lots of material to work with tonight, but probably won’t make the most of it. (In terms of what the polls said afterward, Trump lost all of his debates in 2016 and 2020).
My guess is essentially a draw, but we’ll know more soon.