Jefferson

“Each generation has a right to choose for itself the form of government it believes most promotive of its happiness.”

Madison

“The People were, in fact, the fountain of all power, and by resorting to them, all difficulties were got over. They could alter constitutions as they pleased.”

Wilson

“All power is originally in the People and should be exercised by them in person, if that could be done with convenience, or even with a little difficulty.”

Lincoln

“What I want is to get done what the People would have me do. The problem for me is how to find out what that is exactly.” (Not a Founder, but still a pretty good guy.)