What you don't understand is that controversy and no holds barred commentary in general sells much more readily than bland commentary. This is proven time and again in media ratings. If anything, Rush's ratings should rise as he proves that he is not just another shill for this administration. And it's natural that most people want to hear independent opinions, not biased defensive talk that is tied to personalities not ideas.
Now he just sounds like a fool.
The leftists that he's attracting by his 'controversy' will be gone in a flash. Long time loyal listeners (like me) who support and respect the President are leaving in droves. If he doesn't want to lose a large chunk of his audience permanently, he'd better stop his nasty (and yesterday.....ignorant) bashing.
I don't know about the far rightists who are part of the Bush hating audience, and love what Rush is doing now. They make no sense to anyone except themselves.