Rush had a joke he repeated several times. Here’s a quote from June 10, 2009:
“RUSH: What do Obama and God have in common? Neither has a birth certificate. How do they differ? God does not think he’s Obama.”
This is roughly similar. A brief joke, told in a sentence or two, and dismissable as, well, a joke.
It seems evident that Rush does not want to get into this issue at any length, even to describe what other people are saying about it, much less what he thinks about it.
But he has touched on it gingerly with these occasional brief jokes.
Rush might not be sure which way to go on air about this issue. The jokes might indicate where his sympathies lie, though.