Independent of politics, he’s known to have been a childhood polio survivor. I’ve never seen it admitted regarding him, but he’s certainly at risk for post-polio syndrome. And he certainly wouldn’t be the first politician trying to down play any medical weakness. Basically some the nerves driving certain muscles were killed by the polio, but enough survived to be able pick up the slack so he “recovered” from his paralysis. But those surviving nerves have been working overtime ever since and eventually wear out. Probably not a lot can be done for that beyond celebrating Salk and Sabin for ending the supply of potential new victims. But with PT you may be able to whip more out of whatever nerves still work. If so that could be an argument for retirement, but as having physical rather than mental limitations. We may well not like his political positions, but unlike some Senators I don’t think anyone is accusing him of being demented or otherwise mentally incompetent. At least not presuming no long term damage from the concussion.
I never suggested he was demented. I am saying this is more than your standard 80 year old’s concussion. Your explanation is sound. I think the country has a right to understand when something unusual happens.