Gail Collins: Not to be obvious or anything, Bret, but do you have any predictions about the big debate tonight?

Bret Stephens: No predictions, just the wish that both candidates deliver roughly the same performances they put in four years ago: a coherent Joe Biden and an unhinged Donald Trump. My fears are that Trump will rein it in and avoid being goaded into flatly denying the results of the 2020 election — and that Biden will lose it with some obvious memory lapse, slurred sentence or troubling blank stare.

But here’s my question for you: If Biden’s performance is disastrous, will you join me in calling for Democrats to find a new nominee?

Gail: It’d have to be pretty super disastrous, Bret. Sure, if the president suddenly goes blank and stares at the screen in silence or forgets where he’s speaking and starts commending the Democratic congressional candidate from Delaware.

Bret: Or if he says some of the sorts of things he’s said in the past. Such as, “Poor kids are just as bright and just as talented as white kids.”

Gail: But if Biden delivers boring answers that don’t put Trump in the corner he deserves, I’ll be depressed. There’s no way the Democrats are going to refuse to renominate an incumbent president who has been performing his job very well on all fronts.