Federal Preemption and Sanctuary Cities

In Arizona vs. United States,  the Supreme Court ruled that three of four major provisions of an Arizona law that made certain federal immigration violations also crimes under state law were preempted by existing federal immigration law.  These state statutes effectively mirrored federal statutes, but allowed their enforcement by state law enforcement officials.  Much of the impetus behind the passage of SB 1070 had been the widespread dissatisfaction throughout Arizona with federal enforcement of immigration law under the Obama Administration.  In an interesting reversal, the Trump administration has subsequently been criticized for vigorous enforcement of federal immigration law by states and localities (mostly outside Arizona).  These states and localities have in turn passed legislation creating sanctuary cities/states, i.e., jurisdictions where state and/or local law enforcement will not cooperate with federal immigration law enforcement to enforce federal law against illegal aliens. Post a thread to this discussion forum wherein you apply the Court’s reasoning in Arizona vs. United States to the sanctuary city debate.