I prove your stereotype wrong. Don't know which left wing site you got it from but it ignores Trump won every demographic in the Primary including college educated and well off.
http://www.cnn.com/election/primaries/polls/nh/Rep
High school or less
47%
Some college
39%
College graduate
33%
Postgraduate
25%
His best performing group was "high school or less", the guys with the seven figure salaries, golden parachutes, and corner offices, right? Not so much.
And that is an exit poll snapshot of New Hampshire in February.
Now, going by the simple observation that most Trump supporters seem to be angry people, and most angry people have some reason to be that way, and most people are most resentful when they don't feel they are getting paid what they are worth, that leads back to the un/underemployed, a classic group of people who resent having been laid off and having to seek work below their skill level--especially resentful if they were replaced by some illegal alien or the plant was moved offshore because the company could make more money that way. One thing is certain, being un or under employed just doesn't pay as well.
But, dagnabit, that is logical, and I forgot. Some folks aren't interested in logic, just ballyhoo when they can cherry pick it, and that taken with a macro lens.