I am also a long time listener. I am a “birther” myself, and perhaps Rush is silently a “birther”, but I don’t recall him ever joining in this particular controversy. I have always asked:”There were 2 hospitals operating in Honolulu in 1961, which one was Obama born in? Where is the record?”.
In any case, his father was a British subject, so he could not be considered natural born.
Unless the identity of his father is false, that is.