No, he said Rafferty while well known, WASN’T one of the top three. So certainly not Limbaugh, and I would assume the other two top three spots go to Hannity and Savage, but I’m not really sure. Maybe Glenn Beck. Travis may have just made up a completely prototypical character, too, rather than it being inspired by a specific individual.
I didn’t really have a “#4” in mind. He could be one of a dozen reginoal favorites or Rush fill-ins. Mainly I don’t want to “date” the piece with a real-life name.