Indeed. If the states are soveriegn over immigration, then Arizona has no more right to tell California what to do than California has to do the same for Arizona.
Does Arizona really want to see all the illegal immigrant problems they are dealing with, turn into a legal immigrant problem as the ‘soveriegn state’ of California - right on the border, lets them in and gives them cards and the rest of it?
States are sovereign doesn’t just stop with Arizona. It would be an unmitigated disaster.
Serious question, how do you reconcile state sovereignty with the Supremacy Clause of the Constitution? Seems to me that these two issue are fundamentally at odds in this case.