Rush does these things to rile up the libs. They don’t see anything wrong with demanding that a Supreme Court Justice be Hispanic, Female, or Black.
You make a very good point, and that was something I considered. It it quite possible that Rush was just tossing a figurative bomb towards the libs, to (as you said) rile things up a bit.
But Rush needs to be circumspect with that. He (along with Palin and a few others) represents modern conservatism. And yes, PR matters.