You're only partially right about that. If Rush was simply an "entertainer", he wouldn't have had nearly the success he has over the last couple of decades, and he wouldn't be under near-constant attack from the left.
It's not a stretch to say that he is the voice of conservatism in the modern age. The fact that he tries to make his show 'entertaining' is an added bonus, nothing more.
That said, he royally screwed the pooch today, and I am utterly disappointed in him.
Mark Levin mentioned all these ads against Newt about 1 hr. and 35 mins into tonights radio show and asked “What are they afraid of?”