I think it's more about the apathy around his events than it is the success of Kamala's. This is such a weird cycle since it's the first time in over 100 years somebody who lost a general election after being POTUS is running again so people know what they're getting with that sack of shit. Basically he can't afford to even lose a sliver of his support since it wasn't even enough back in 2020 so between 1/6 and his dance party there's no way he's not losing a big chunk of his support. I'd be shocked if this isn't called before midnight on election night.
Also, (and I know this is purely anecdotal) I was just in one of the most red towns in one of the most red counties in PA and I didn't see a single one of his signs on a street w/ 60+ houses while also seeing multiple signs for Kamala. That shouldn't happen unless something is really wrong with the GQP candidate.