The people who elected Trump did so because they weighed the choice and voted to direct the nation away from encroaching Progressivism (and the Clinton kleptocracy…as described by Orwell’s Animal Farm).

Your assertion that the Trump voters are less intelligent is an illustration of the moral superiority that repels them.
Those less educated voters are people who were not contaminated by the progressive poppycock that has metastasized from the university elites into the better educated cohorts of the population.

Regarding the assertion that Trump himself is stupid; what some see as stupidity may in fact be nothing more than lack of education and clumsiness.
A man who demonstrated an ability to prosper in the dog-eat-dog Manhattan real estate/construction industry which is regulated by the corrupt NYC Democrat political bureaucracy and manipulated by unions controlled by the Mafia is not a man who doesn’t know his way around the block.

On international matters, his way of doing business does not translate well into the niceties and slippery deviousness of diplomacy.
That upsets a lot of people (including me).
On domestic matters he has discovered that the political machinery of the Washington swamp is even more complex and devious than the NYC real estate world.
In both areas, his lack of ability to articulate the soothing rhetoric of a polished politician is a handicap and a reflection of his abrasive, impulsive personality.

He often appears to be in over his head…but the end results are yet to be seen.
He is something never before seen on the nation’s or the world’s stage.

The people elected Trump knowing that he is a narcissistic egomaniac with a history of philandering and questionable business practices.
Before he was elected he clearly demonstrated that he is a crude, loudmouth BullShi**er.

Out of desperation, a less educated but equally intelligent voter cohort chose him over Hillary.
They were not fooled.

It is unlikely but possible that interference by foreign adversaries tilted the election and that otherwise Hillary might have won.
That however, is a different matter having to do with communication, social media, etc..