I haven't read through this whole thread, so this has surely already been pointed out...
There are a ton of audio and video clips out there recounting Rush's racism, bigotry, and general meanness. But I think that - by far - the worst thing he's done is something he says 50+ times every show. "Liberals hate America." "Liberals want to destroy this country." "It's just another example of how liberals are pure evil, folks."
That shit has taken a giant toll on this country.
After decades of repetition, his audience has heard it so much that they swallow it down like a cult. Nobody flips on the AM radio and then thinks critically and says, "Yeah, I have friends/family with liberal politics, and I know for a fact that they are not a demon who wants to destroy America."
Rush has done as much to divide this country as any person alive.
And he is the personification of hypocrisy. He rails against immigrants, and in racist-coded language (e.g. "thugs") he argues for stiff penalties for criminals. Then he goes back to his mansion and sends his undocumented housekeeper to fetch him vast quantities of illegal narcotics. He calls for "family values" and faith-based morality, then heads to the airport to take a private jet to the Caribbean with a woman who is not his wife, and a bottle of viagra prescribed to someone else.
As I type that last paragraph, it occurs to me that we shouldn't have been surprised by the willingness of today's white evangelicals to support an obviously immoral and un-Christ-like cult leader.