While I agree the man is blowhard, arrogant, pontificating, etc.
He was, for the most part, a lone voice in a Liberal maelstrom back in the '80s (ahh Reagan, damn I miss that man), and he is often very observant. Scientifically, his reasoning is embarrassing (if I happen to be listening, I just turn him off when he tries to speak about science) even though he is often correct in his final conclusions.
He has done a lot to beat back liberalism in this country, he spoke out when most would not, and he paved the way for whomever you might currently be listening to on AM (as AM radio was about dead before Rush revived it--like it or not) for that I give him a pass on a lot. He doesn't do much for "our" personal piece of the Constitution, but at least he supports it because it is there.