You're taking his bait superbly by thinking that the truth wins you the game of democracy. To call him "dumb" is to severely underestimate the strategies potential president have used in their rise to power. Or in other words, did calling him an idiot get your side any concessions, any retaken ground?
Instead of taking Trump's bait, I'd highly recommend reading Robert Caro's books on Lyndon B. Johnson. You'll never look at politics the same way again.
Of course his dumbness has appeal. That’s why he won. That doesn’t mean he’s not an idiot.
I told you to read Robert Caro's series on Lyndon B.Johnson because it opens your eyes to the political process. Do you think Johnson campaigned as a Roosevelt man because he liked Roosevelt? Hell no, he was an opportunist.
W had a superficial dumbness that was largely cultivated. Beneath that he had at least a basic understanding of the issues.