For the record: I'm anti-left, so this isn't some liberal rant.
Every time I listen to Trump I am astonished how incoherent he is and how we answers questions. He seems like a sub-120 IQ person to me. He simply does not sound like an intelligent person. I suspect some of this is due to an age related cognitive decline as I'll admit he does sound much better in earlier interviews in 1980s or 1990s.
Yet he was highly successful in real estate business. Does this change your perception of the field in some way?