This was my reaction.
To be fair, I'm pretty sure they're basing 100% of their analysis on his public appearances, which is likely when he's at his best. He's either following a script or he's been coached on what to say immediately prior to going in front of a camera.
In any case, America is cooked. He's not going to step down, and there's still a nontrivial amount of support for him to be installed as grand pubah.
That's optimistic, I expect them to prop him up and have him continue being their leader well after he starts to decay, weekend at Bernie's style.