I agree with Cain, for the most part, on that point: the states are the ones closest to the problem and should be allowed to deal with it.
There are some points at which the fed gov would be better, or should at least be involved, particularly to standardize the process, which ultimately aims to remove illegal immigrants.
Border states especially ought to be given (no pun intended) wide latitude. Much as in the case of Louisiana having the authority to reject federal troops after Katrina hit, the fed gov should be mainly there by invitation only.
And this is regardless whether Republicans prevail in the elections or not. Even a Republican Congress and President aren’t going to do better than to get behind the states.
(Of course, where established law already stipulates that the federal government has the authority, the fed govt can and should function in those regards.)
Ten or twenty states with laws like Alabama’s, I think we’d have a much smaller problem overall.