Mencken called it in 1920

"[W]hen a candidate for public office faces the voters he does not face men of sense; he faces a mob of men whose chief distinguishing mark is the fact that they are quite incapable of weighing ideas, or even of comprehending any save the most elemental -- men whose whole thinking is done in terms of emotion, and whose dominant emotion is dread of what they cannot understand. So confronted, the candidate must either bark with the pack or be lost... [A]ll the odds are on the man who is, intrinsically, the most devious and mediocre -- the man who can most adeptly disperse the notion that his mind is a virtual vacuum. The Presidency tends, year by year, to go to such men. As democracy is perfected, the office represents, more and more closely, the inner soul of the people. We move toward a lofty ideal. On some great and glorious day the plain folks of the land will reach their heart's desire at last, and the White House will be adorned by a downright moron."

- H. L. Mencken, in the Baltimore Sun, July 26, 1920

(emphasis mine)