"...And if they can't do that they want to destroy him "
It's not gonna happen. Rush has some deep roots. This is the reason they hate him with such passion. He exposes their idiocy, and people listen and agree. He sparks many avenues of thought that "they" would prefer the liberal lemmings of society never hear.
Of course, the hard-core liberal would only listen to Rush in order to test his blood pressure medications effectiveness.