Biden was kept hidden and carefully managed and his staffers had to cut him off and remind him of the current year. You may not like Trump, but everyone that works with him closely, recognizes he is more intellectual than his public persona would seem to imply.
Most elderly people are capable of sitting around for hours rambling, especially on political topics. In fact, what's difficult is getting them not to. Occam's says that affirming the emperor is definitely wearing clothes is just the type of politically correct fluffing that happens in every autocracy. Lying to ingratiate yourself with flattery certainly costs less than paying larger bribes.
Dementia presents in the content, not the length. Plenty of people with dementia talk a lot; the problem is much of it is nonsensical.
What's been your favorite response of his to the Epstein situation?
LOL. Sure he can ramble for hours. But if you read a transcript of any of those conferences, he's literally incomprehensible, can't string more than two logical sentences together. It's just a jumble salad of key trigger words. And when he does present facts, it's either incorrect or an outright lie. It's an embarrassment, frankly.
If you're truly honest about doing that, you should wind up being disgusted 24x7.