H.L. Mencken might have been as famous in his day as Limbaugh is now. Father Charles Coughlin had a radio audience of millions for his political views. Generations change, and so does the mass media they prefer, as well as the way they think of that mass media. The leftist cultural juggernaut goes on.
Read your history on Father Coughlin. FDR set out quite deliberately to silence him. He used FCC rules and postal regulations to pretty much shut him up (though a new Archbishop in Detroit sealed the deal by ordering Fr. Coughlin to be quiet and go back to being a parish Priest). The rule that even an overnight-shift disc jockey had to pass an FCC licensing test before touching a turntable was passed specifically to get Coughlin off the radio.
He may have been a Nazi-sympathizing Socialist rabble-rouser, but his First Amendment rights were trampled on perhaps more brazenly than any other American in our history.