As I understand it, Alan is on 700AM KSEV because the program director (the conservative Dan Patrick) wanted to buy into some Fox radio programming so that he could also tap into Fox News for breaking events (like Gulf War II).
Dan has talked with Alan on the air before (on local broadcasts) and Alan resorts to throwing temper tantrums. I believe that they've come to the conclusion not to talk to each other on the air anymore. I don't know why this show gets broadcast; it does little to advance real thought. The entire show is spent shooting down Alan's arguments. It shows the vacancy of political thought on the left but we already knew that.
On 90.1FM KPFT (tax payer supported socialist/Pacifica radio) the logic even become more strained. Is it any wonder that I switched over to 950AM KPRC to hear Michael Savage? These are the "talk" options at that hour (other times I just listen to a CD when I'm in my car).