Are we generally considering Trump to be smarter than he appears? His actions, and the underlying actions (unawareness of EO's, surprise at various aspects of taking the presidency, the things he can't lie/bluster about) seem to present an aura of incompetence.
If I were to guess where Trump scores on a standard IQ test I'd estimate about 120 or so. Not a genius but not stupid, however that doesn't count for much when the question of intelligence is considered. There are things for which no quantifiable standards exist.
Consider that the man is the President. He beat Hillary and his supporters and the majority of Dem leaning here consider them stupid on a good day (but they still lost). Note Bush was "shrub" and Edwards was going to wipe the floor with Cheney. Nope.
The mistake was underestimating and misunderstanding the opposition and instead of close inspection and considered thought, a predetermined framework based on *what should be* was substituted for "what is". Hubris won the day in favor of Trump. His competence in office isn't really the same as his ability to manipulate.
Now as to an analysis of Trump outside of that? How long a TL;DR are you asking for? Nothing is simple.