Let me be careful to state that I don't favor Trump. His history shows that he may be quite willing to skewer his investors/voters, if it furthers what HE wants.
However, I don't believe that Trump supporters are necessarily any less intelligent (or more stupid) than the average American voter. Most of them are prone to emotional, unthinking decisions.
The Z Blog makes a reasonable case for Trump's popularity. The comments are quite good, too.