George Bush springs to mind. Though maybe he actually was a patsy.

Let's be fair here. Liberal bias requires people to either believe anyone with conservative leanings MUST be stupid or the received wisdom that liberal philosophies are naturally correct must be incomplete. There's no real choice here, every single person on earth will assume everyone else is stupid before assuming they may be wrong.

That's the exact opposite of liberal, "open to new behavior or opinions and willing to discard traditional values."

There are plenty of intelligent people in all parties, disagreeing with them doesn't make them idiots. Greenspan comes to mind, I think his basic market beliefs are wrong, but don't think he's an idiot, I have read his book. GW is a lot closer to idiot level because of his demeanor AND his actions, but let's be serious few actual idiots make it that far, just not all of them are way above average intelligence.

But I don't actually think GW was an idiot by the sheer fact that he surrounded himself with some of the most brilliant conservatives of the time. Cheney is evil incarnate, but few would call him an idiot. The same can be said about his secretary of defense, donald rumsfield. Rumsfield is the shining example of "doing it right" and being a hard charger.That being said, the two of them colluded and it caused badness.

Knowing you're outclassed isn't the mark of an idiot, but of a brilliant mind. Trump thinking he has an excellent memory and is the best in everything is the mark of a true idiot.

Maybe wasn't clear, GW isn't an idiot, but closer than most leaders, I'd say. Did GW choose all those people, or were they all pretty much from the conservative cabal that got GW elected? I think things like Iraq lack of evidence due diligence and Katrina appointing super inept guy are the things that make me think GW's personal selection skills weren't great, he did have brilliant advisers as you listed.

I don't think Trump is an idiot, more of a huckster with extreme emotions, but certainly loves to pander to the idiot mentality.

Dan Quayle is really the only true idiot I can call to mind who had a major position in a US party I can recall.

There are two essential traits I look for in a leader. They should have goals that align with my own, and they should advocate for policies that could reasonably be expected further their goals. At least in American politics, I usually see the term "idiot" applied to politicians who pass the first test but fail the second.

I suspect George Bush's bumbling persona was put-on as well (or possibly honed over years) on the basis of this youtube[1] video comparing his oratory style between 1994 and 2004

1. https://www.youtube.com/watch?v=JvknGT8W5jA