He's an absolute moron but he's also the poster child of failing upward. As long as you're rich in the US it's nearly impossible to actually fail. He's squandered most of the wealth his sleazy father left him, but he still has enough left over to be completely insulated from the consequences of his actions. His children won't be as fortunate unless they're a lot smarter than he is and actually manage to make some money instead of constantly losing it.
He was smart enough to recover from that and become president of the US. He's a rapist, conman, felon, and he still became leader of the free world and is now taking it over as a dictator. That is not stupid. Did he have super intelligent help? Yes. Is he being used as a tool, who the fuck cares?