I think one reason they hate him now, is that he is bypassing the media system they have set up. He has his own successful network with no debt and no liberal bosses to reign him in. And he continues to grow.
That is true - astro-turf groups tried to get him kicked off the radio (after being able to do it on Fox) and he turned around and formed his own company. It has to suck when a well planned Alinsky blows up in your face.