It's a policy. And, in his position, a good one.
Nonetheless, you can tell three things for sure -- just by listening to his show.
a. Romney is now lower than dirt.
b. Paul is a kook.
c. Either Gingrich or Santorum would be fine by him.
Why is it a good policy? Not to share with your listeners who you are voting for? I think that is dishonest. Think about it, maybe I’m wrong. But why shouldn’t we know who he votes for, when he keeps promoting conservative principles?