In other words, McCaul wants somebody who is even less committed to enforcing immigration law than Napolitano was (her tough talk notwithstanding).
I don't think that is his intention, but he is making a dumb move, in effect asking to be exploited by Dems and RINOs. Why not just say O should appoint somebody who will be faithful to the rule of law. Of course he won't. But even if Obama appointed Joe Arpaio, he could replace him as soon as the illegals got their legal ststus.