Of course the man is an empty suit and an empty head. He cannot appear where he may have to think and reply off the cuff because he has nothing of his own to say.
He is really not capable of performing the duties of POTUS and is the perfect puppet for the Democratic party to implement its Communist agenda.
I think he has core beliefs. They are based in racism, hate whitey, "Black Liberation Theology", radical Marxism, anti-capitalism, and anti-Americanism.
When he's teleprompter-less, it requires more effort than his limited intellect can muster to filter out the stuff that he knows would be political death to espouse. That's why we get the "uh, um, uh, and..." out of him.
He's trying his best to filter his beliefs so he doesn't say something stupid like "let's spread the wealth around, it's just neighborly".