WHY ARE AMERICAN CONSERVATIVES SO MEDIOCRE?

I'm not talking merely about talk radio gasbags like Mark Levin but also small fry like this fellow, a retired professor, who writes this about Rousseau on Newt Gingrich's Fundie web site,

But detached from his evil being Rousseau’s enthralling words took flight. Few remembered him as the “monster” David Hume described. Rather, he became, in the words of George Sand, “Saint Rousseau”—the guiding light for philosophers ranging from Kant to Schiller and Mill and novelists such as George Eliot and Victor Hugo.

To my knowledge, Rousseau had no or negligible influence on Kant or Mill.  In addition, Schiller was a poet and playwright, not a philosopher.