The issue isn't mere lack of intelligence. It's people who think they can only advance by harming others. Their main complaint about Trump is that he's not doing that enough: "he's not hurting the people he's supposed to be hurting".

The undecideds are the ones who are dumb. That, and cross-pressured extremists - racists who know that Republicans screw them, so are torn between voting between their bigotry and their pocketbook.

“If you can convince the lowest white man he's better than the best colored man, he won't notice you're picking his pocket. Hell, give him somebody to look down on, and he'll empty his pockets for you.”

― Lyndon B. Johnson