On the state side of the equation, the Tenth Amendment provides that “the powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.” The states have an undefined mass of “police powers,” most definitely including control over their own law-enforcement apparatus. The court has also enunciated the “anti-commandeering principle”: Even when acting within its proper powers, the federal government cannot reach down and require state legislators or executive officials to carry out federal programs.

In other words, under the Constitution, relations between state and federal governments focus on what each party cannot do to the other, rather than the reverse. Congress can pass laws, and the feds can enforce them, but they can’t make the state governments enforce them; states, conversely, can refuse to enforce federal law, but can’t stop the feds from doing so in their territory.

This dance of federalism is thus a little like the strange playground version of “Simon Says” I played as a kid, in which the “Simon” player issued instructions containing double and triple negatives to confuse the players about whether to step forward or stop. (“Do not not step forward—not!”) That weird negative standoff gives rise to the third significant text in this case, 8 U.S.C. § 1373: State and local governments and officials “may not prohibit, or in any way restrict, any government entity or official from sending to, or receiving from [ICE] information regarding the citizenship or immigration status, lawful or unlawful, of any individual.”

Can the federal government require states to turn over information they have? Probably not; that would be commandeering. Can the states bar the federal government from getting information that’s otherwise available? Almost certainly not; that anti-federal discrimination would trigger pre-emption. But is saying, “States shall not have a policy of not doing something because not doing it obstructs federal law” really just a sneaky way of saying, “You shall have a policy of doing that thing because doing it helps federal enforcement”? The constitutionality of 1373 is not yet settled.

Within that framework, how do California’s three bills play out? The state can certainly ban its own facilities from contracting with ICE to detain employees; the state almost certainly can’t bar private facilities from doing the same. Can it require inspections of state facilities being used for federal immigration purposes? Probably. What about private facilities? The state can generally supervise or inspect public or private facilities—jails, hospitals, nursing homes—but how sharply, if at all, can it specifically target private facilities that deal with ICE? There are reasons to do so—these private detention centers are rife with abuses—but the U.S. argues the inspections are intrusive and obstructive.