Just to say, I'm increasingly uncertain about how truthful it really is that JD Vance was the worst possible pick for Trump and the best case for the democrats. If the matchup was still Biden, perhaps. But the thing is, Kamala has the black vote, Indian vote, and to a lesser extent the Female vote on lockdown now. She's the candidate, she's got them turning out hard, any attempt for Trump to win some over with someone like Carson or Swaney would have been utterly undone and rendered moot. There's a bit more of an argument for the women, but Nikki was too troublesome and most of the other options are either old or look old. Trump needed someone young to shore up that flank, who won't depress his base(or will help boost them, albeit after the shooting that's not needed), helps him look sane and the ticket by proxy, and is at least potentially helpful with either the rust belt whites or Hispanics(who are the actually gettable ones against Harris). Vance is young, helps the base, and might edge out a few rust belt voters. He's useless with Hispanics though and doesn't help the moderate issue. So still not great, but a lot of the picks people were worried about like Ben Carson would have been completely neutralized by Harris with hindsight. The threat of Trump pulling over key black voters is a dead threat and that's not where the VP sway matters most right now.

The two picks that would be better than Vance(and the two you should feel worried about Trump switching to in the next 10 days) are Doug Burgum and Glenn Youngkin. Burgum has a lot of the same advantages as Vance, and he comes off as a lot more sane and less stupid, albeit at the cost of being older than Harris and most of her VP choices. That one could go either way honestly and I doubt Trump would risk the optics for someone barely better, but if he did he could be an issue especially as it kills stories like OP. The real threat would be Glenn Youngkin. He's younger than Harris by two years and younger than almost all her VP options. He's a white guy, he comes off as more moderate than Trump or Vance by comparison, but not so much to risk depressing the base like Haley, and he's younger(Also he has Young in his last name, easy to work with). The biggest threat with him though is that he'd give a boost in Virginia, and while Post-Biden that's not a death sentence it forces Harris to commit resources and time to a state the Republicans don't really need to win and the Democrats really cannot afford to lose. Also both Burgum and Youngkin have tech industry roots and heavy ties. They might not be Vance tier loyalists, but they'll sing the tune of the Paypal Mafia if they must.