Not really the point of my question. If, as Megyn Kelly and this article seem to be saying, that the authority for state and local governments to enforce immigration laws already exists, and has been upheld by the Supreme Court, then they could have been enforcing the law all along. (And Sheriff Joe has been doing that based on some existing law.)
I do wonder if there is some question of jurisdiction re: the SCOTUS decision referenced in this article.
All political...