And, what is his mental state? He's old. But he still seems sharp, just lower energy. That doesn't mean he couldn't do the job....And Trump is only 2 years younger....You really have no clue what you're talking about, just parroting right-wing smears. As mentioned, if you look at the timeline, he got COVID. That could certainly sap the energy out of even a younger person. Maybe he realized he wouldn't win, and it was more important to keep Trump out of power than his political ambition.
I think that whole "desperate" feeling is coming from MAGA, who thought they would just sail into November and win. Now that she's kicking Trump's ass, they are trying to pull out all the stops to smear her. And, it really is pretty pathetic to watch. The whole Trump campaign reeks of desperation, he trying to find a good nickname for her and still failing.