You and Aristophanes, in The Frogs, 405 BCE, as noted and cited in the article.
There's also H.L. Mencken's "Brayard vs. Lionheart", 1920 CE:
[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 count himself lost. His one aim is to disarm suspicion, to arouse confidence in his orthodoxy, to avoid challenge. If he is a man of convictions, of enthusiasm, of self-respect, it is cruelly hard.
There's also H.L. Mencken's "Brayard vs. Lionheart", 1920 CE:
[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 count himself lost. His one aim is to disarm suspicion, to arouse confidence in his orthodoxy, to avoid challenge. If he is a man of convictions, of enthusiasm, of self-respect, it is cruelly hard.
http://amomai.blogspot.com/2008/10/hl-mencken-bayard-vs-lion...
Other writers have drawn from Jean Piaget's models of intellectual development, and the distribution of such capabilities in the general population.
I strongly recommend reading the full piece. Several times.