Do the American people realize that Trump does not have the intelligence necessary to be President?

It's not an overall intelligence problem as much as skills in the wrong areas and many bad characteristics inappropriate for a President of the United States.

Speaks without thinking as a total lack of self-control and respect for decorum.

It is a huge narcissism with lack of empathy and delusions of grandeur.

It is lack of understanding for common people and definitely race insensitivity.

It is a commanding without ability to get true support from people with the knowledge of expertise nor respecting others authority. That's called stubborn and imperious.

He passes on conspiracy theories and unproven illusions of fact.

He has said very stupid things, probably without understanding their meaning.

Literally invisible F-35 jets, coal without dirt as "clean coal", raking leaves in forests to prevent forest fires, internal use of disinfectant poisons, nuclear bombing hurricanes, windmill noise causing cancer, airfields captured in the 1700's, and more.

He wanted massive nuclear bombs and star wars level space forces.

Extremely mentally unstable rather than lack of intelligence as he is able to manipulate uneducated people using logical fallacies and techniques of speech.

Cheating conniving SOB more than idiot, though he appears to be an idiot to intelligent people. 

Do the American people realize that maybe it doesn't really matter who's president?

.. and the people who voted for him didn't have the intelligence necessary to vote.

Doh, I don't know. If I had a brain it would rattle around like a BB in a Boxcar.