Why do people keep saying he is smart?

Whenever any pundit is critiquing him, they often will say he is high IQ or smart. They act baffled by his actions and thought processes. Maybe it's graduating from Duke, or how well spoken he is.

One thing I have observed from being around highly intelligent people is that people tend to overestimate the overlap between how eloquent someone sounds and how smart they are. In fact when you interact with genius level people, in my experience, social and communication skills actually begin to get worse.

Moral: when truly judging intelligence forget how you feel or what you hear, and look objectively at a person's track record. How can a flat-earther who is destroying their own character and diminishing their career prospects and ability to influence be considered truly smart?