I’ve only interacted with two dementia/alzheimer’s patients, so I’ll admit I don’t know much about the conditions.

While yes, they could get belligerent and uncooperative, but largely would agree with pretty much whatever you were saying, as long as you weren’t using a mean tone. Basically they were thought sponges that had no problem agreeing with whatever you said, and even repeating it for a short time before losing it.

Trump is clearly a thought sponge for whoever he last spoke to that wasn’t immediately adversarial to him.