I'd say a large part of the country had the same sentiment about George W Bush. I'm not sure whether that was true or just an act, though. In politics, I think the opposite of Hanlon's razor has often been applicable. It's easy to feign ignorance to avoid responsibility.
That being said, I believe there has been an increase in genuinely dumb people in American politics in the past ~15 years.
George W. Bush scored well above average on standardized tests. People who worked with him and have no reason to lie report that he was deeply engaged on policy issues and had a good command of the facts. And yet despite all that he still managed to make some truly terrible decisions that still negatively impact the country today.
It was really the mainstream media who falsely labeled him as an idiot. The "chattering class" who make their living by speaking and writing tend to denigrate others who aren't particularly good at those things, regardless of their other abilities or achievements.
History suggests that a divided America tends to elect less effective leadership. The goal of the electorate becomes less about electing someone who will support your causes and more about electing someone who won't screw you over.
We saw this in the so-called "bumbling generation" that led up to the Civil War, and when a President widely regarded as more charismatic and competent President was elected, several states panicked and seceded.
