I'm subjected to a few hours of Fox News/right-wing YouTube a week, and it's certainly felt like the vibe has shifted. Reading between the lines with some of the talking heads, it sounds like they'd rather Trump lost and the GOP made gains in both the House and the Senate.
They can still run the party status quo ante that way for at least a little while. If Democrats get through voting rights legislation, the GOP will be forced to come up with an actual party platform beyond "loot the treasury."
This was also my takeaway from the debate. Trump looked weak from the jump when he let Harris take the lead in shaking his hand. He was on the defensive all night. All this capped off by a cringe-inducing "I saw people on television talking about it" when fact-checked on the immigrants eating cats and dogs comment (which was also batshit insane enough to lose some of the 67 million watching). Truly an "okay, let's get you to bed, grandpa" moment.
The substance behind his words has never mattered to his supporters, no matter how vile or dissembling, but the vibe absolutely does. They won't turn around and vote for a Black woman, but there has to be a loss of enthusiasm that comes about from this, if not breaking the spell entirely for a few people. He looked old, small, and weird.