You cannot have a populace that is more and more ignorant of science, history and philosophy and still embraces the ideals of the Enlightenment that allowed for the principles that divide this nation from the more primitive nations of the world. Such people are infinitely more susceptible to accepting fairy tale explanations for the mechanics of the universe. It's simpler and it makes their heads hurt less.
On top of all of that, there seems to be a celebration of ignorance. You mentioned Jefferson. Can you imagine someone of that intellect and variety of pursuits rising in modern politics? Da Meatheads would villify him as some elitist egghead from the coast. Not a real American. Theodore Roosevelt read a book a day. Has Dubs ever read a book from cover to cover? If you ever get the chance to listen to some of the more obscure members of the House of Representatives when they appear on Fox or MSNBC. Chris94 once corrected me when I lamented the existence of Barbara Boxer by writing that there are 200 bigger dummies in the House, and he was entirely accurate. You could probably find more competent and intelligent members at your local dive at 1 AM on a Friday night.
We're doomed and everyone here above the rank of idiot knows it. Fortunately, you and I will probably be dead by the point we've reverted to some Hobbesian state of nature.