“The Founders just assumed that American men were men of integrity.”
You are the winner for being concise.
It went far beyond that, clearly. They also assumed Americans of leadership caliber could not be mentally-challenged, felons or children. Further, they were also educated beyond the the common denominator, and unquestionably possesed common sense.
That, of course, would disqualify at least 25% of our elected officials.
My personal assessment from their behavior and reasoning power, it's closer to 50%.
Isn't egalitarianism wonderful?