The Tenth Amendment Defense of Sanctuary Cities, and Where It Runs Out

I am going to say something that will annoy some of my friends. The strongest legal argument for sanctuary cities was written by Justice Antonin Scalia. Yes, that Scalia. The same justice conservatives quote at every banquet, the originalist's originalist, wrote the opinion that the sanctuary movement leans on hardest. If you did not know that, you are about to lose an argument to a city attorney who does.

That is a fact worth sitting with, because the right has a bad habit on this issue. We shout "sanctuary cities are lawless" and stop there. Then somebody in the audience who has read a bit of constitutional law points out that the Tenth Amendment protects the states from being drafted into federal service, and we have nothing to say. I would rather we be the side that knows the other side's best argument cold. So let me state it fairly, as a good debater would, and then show you where it stops. It stops sooner than the sanctuary advocates admit, and later than some of our own talk-show voices claim.

What a "sanctuary" policy actually is

The label covers a lot of ground, and the loose use of it causes half the confusion. There is no federal definition. In practice, it means a state, county or city policy that limits how local government employees assist federal immigration enforcement. The policies vary. Some bar local police from asking about immigration status. Some refuse to honor requests to hold a person in jail past the time he would otherwise be released. Some limit sharing of information, or bar federal agents from jail space. Some are written as ordinances, some as police department policy, and some as state statutes.

Keep one distinction in mind throughout: declining to help is not the same as actively obstructing. The constitutional protection is strongest for the first and weakest, or gone, for the second.

The steelman: the anti-commandeering doctrine

The strongest version of the sanctuary case goes through three Supreme Court decisions.

New York v. United States (1992). Congress passed a law that gave states a choice: regulate radioactive waste according to federal instructions, or take title to the waste. Justice O'Connor wrote that Congress may not commandeer a state's legislative process by compelling it to enact a federal regulatory program.

Printz v. United States (1997). This is the Scalia opinion. The Brady Handgun Violence Prevention Act required local chief law enforcement officers to run background checks on handgun purchasers during an interim period. Sheriffs in Montana and Arizona sued, and the Court, by a five to four vote, struck down the requirement. Justice Scalia reasoned that the federal government may not compel state executive officers to administer a federal regulatory program. The Constitution divides sovereignty between two governments, he wrote in effect, and dual sovereignty means the national government cannot press the states' officers into its service.

Murphy v. National Collegiate Athletic Association (2018). Justice Alito wrote that a federal law forbidding states from authorizing sports gambling violated the same principle. The anti-commandeering rule is not limited to orders that tell states what they must do. It also bars Congress from dictating what state legislatures may or may not enact. The Court said it comes from the structure of the Constitution, not from any single clause.

Put those together and the sanctuary advocate says: immigration enforcement is a federal job. Federal law gives Washington the authority. If Washington wants local jails and local police to do its work, it has to ask, and the locality can say no. A sheriff who refuses to be an immigration agent is doing precisely what the sheriffs in Printz did, and what the Constitution protects. That is a strong argument. It is not a trick.

Notice also that conservatives have used this doctrine proudly. Printz was a victory for gun-rights supporters. Many conservatives have cheered counties and states that declare they will not use their resources to enforce federal gun rules they consider unconstitutional. If the principle protects a sheriff who will not run a federal background check, it is hard to say it fails to protect a sheriff who will not hold a person for federal immigration agents. I explore that parallel in The Tenth Amendment Rule That Protects Red States Also Protects Sanctuary Cities.

The answer, point by point

Now the work of showing where the argument stops. There are five places.

One: detainers are requests, and that cuts both ways

When federal immigration agents want a local jail to keep a person after his scheduled release, they send a detainer, a form asking the jail to hold the person for a limited time so agents can take custody. Federal regulation sets the limit at 48 hours, not counting weekends and holidays. The regulation itself calls it a request.

Sanctuary jurisdictions rely on that wording. Courts have agreed that detainers are requests, not commands. The Third Circuit said so in Galarza v. Szalczyk (2014), and the point also guards cities against being forced to comply. A city can decline a request. That is the anti-commandeering principle working as designed.

But the same logic shows the limit of the sanctuary position. A request is not a prohibition. A city that merely declines to hold a person is on strong ground. A city that goes further and tries to stop its own employees from even telling federal agents when a person is being released, or tries to bar federal officers from doing their jobs in public, is doing something different. The Tenth Amendment protects the refusal to help. It does not protect interference with federal officers who act on their own.

The practical answer for federal authorities is that they can arrest people themselves, in public places, at their homes or workplaces, and anywhere else the law permits. Declining to hand over a jail inmate does not stop that. It only makes it more difficult and more dangerous, a point sheriffs have made about arrests in neighborhoods versus the secure setting of a jail.

Two: information sharing, and the statute Congress wrote

Section 1373 of Title 8 says that a federal, state or local government entity or official may not prohibit or restrict any government entity or official from sending to, or receiving from, the immigration agency information about the citizenship or immigration status of any individual. A companion provision says the same about maintaining and exchanging such information.

The law is clear in its words, and many sanctuary policies that restrict sharing of status information run into it. But there is a catch, and honesty requires that I tell you. After Murphy, a serious question arose about whether section 1373 is itself an unconstitutional commandeering of state policy, since it tells states what they may not do. Lower courts have not agreed on the answer. Some have found that the section survives, particularly because it concerns narrow information about status and not the running of a state program. Others have been skeptical. I will not predict how the Supreme Court would rule. If you plan to cite 1373 in an argument, look up the latest rulings first.

What I can say is that the information-sharing fight is stronger ground for conservatives than the detainer fight, because refusing to share a fact is not the same as refusing to perform a federal task. It is also where Congress could draft more carefully if it wants a law that survives.

Three: harboring, and where the line is

Section 1324 of Title 8 makes it a federal crime to conceal, harbor or shield from detection a person who is in the country unlawfully, knowing or in reckless disregard of that fact. Some on the right argue that sanctuary officials are violating it by definition.

That claim is much shakier than it sounds. Harboring is about conduct that conceals or shields a person from detection, and merely declining to participate in enforcement is not the same as hiding someone. I know of no court that has held a sanctuary ordinance to be a harboring offense, and the question is largely untested. A responsible conservative should not promise voters a prosecution that the case law does not support. If an individual official takes active steps to hide a specific person from federal agents, that is a different story, and the statute reaches it. But the statute does not turn a policy of non-cooperation into a crime.

Four: the money, and the Spending Clause

If the Tenth Amendment protects a city from being commanded, can Washington instead pay for cooperation? Here the doctrine is South Dakota v. Dole (1987). Congress threatened to withhold a small percentage of federal highway money from states that kept the drinking age below twenty-one, and the Court upheld it. Congress may attach conditions to federal funds if the conditions are in pursuit of the general welfare, are stated unambiguously, relate to the federal interest in the program, and do not violate other constitutional provisions. The Court has also warned that the pressure cannot be so great that it amounts to coercion. In NFIB v. Sebelius (2012), the Court found that threatening to take away existing Medicaid funding from states that refused the expansion went too far. I tell the Dole story in more detail in The Drinking Age Story Shows How Washington Buys Control of the States.

For sanctuary jurisdictions, the lesson is that conditions on federal grants are a legitimate tool, but they have rules. The condition must come from Congress. When the executive branch has tried to add its own conditions to grant programs without clear authorization from Congress, courts have often ruled against it, and federal appeals courts have not agreed with each other in every case. So the lawful route for a conservative who wants this lever is simple: persuade Congress to write the condition into the statute, clearly, and tie it to the purpose of the program. A condition that Congress writes will fare much better than a condition a department invents.

Five: the Supremacy Clause and the limits of non-cooperation

Finally, the Constitution's Supremacy Clause makes federal law the supreme law of the land, and states cannot obstruct its operation. A state can choose not to lend its own employees to a federal effort. It cannot, for example, forbid federal agents from doing what federal law lets them do, or punish federal officers for carrying out their duties. The Ninth Circuit, in a 2019 decision involving California's sanctuary statute, upheld most of that law as a lawful refusal to assist, while the federal government retained the ability to enforce immigration law by its own officers. The Supreme Court declined to take the case.

The cleaner way to say it is that federalism gives each government its own sphere. The states keep control of their own people and resources. The nation keeps its own enforcement power. When a city says "we will not do your job," it is within its sphere. When a city says "you may not do your job," it has crossed into the federal sphere, and the Tenth Amendment will not protect it.

Where federalism leaves honest room for both sides

So where does that leave us? With a result that satisfies neither extreme, which is usually a sign that the law is working.

What sanctuary advocates are right about. Washington cannot force a city or state to staff federal immigration enforcement. A detainer is a request. A local government may choose how it spends its own police time and jail space. These are not loopholes. They are the Constitution's design.

What they are wrong about. The Tenth Amendment does not let a locality block federal agents, hide people from them, or restrict the basic exchange of immigration-status information, at least as Congress has written it in section 1373, subject to the doubts above. And "sanctuary" cannot mean that federal law stops at the city limits.

What conservatives can do. We have lawful tools. We can write clearer statutes for information sharing. We can attach clear conditions to funding. We can expand voluntary partnerships, such as the 287(g) agreements that let willing local agencies assist, which I describe in A County Sheriff's Playbook for Joining ICE Under 287. And at the state level, we can use state law to direct a state's own cities, because the Tenth Amendment protects states from Washington but does not protect cities from their own state legislature. Cities are creatures of the state. That is the part of this debate that gets the least attention, and it is why red-state legislatures have had the most direct power to do something. For the wider picture of what states can and cannot do on immigration, see What Can a State Do About Immigration? Ten Answers From Arizona v. United States.

The verdict

A good argument deserves a good answer, and the sanctuary position deserves one. The cheap answer is "they're lawless." The better answer is "they are right that Washington cannot commandeer them, and wrong that this lets them obstruct, and the remedy for what we dislike is a clear statute, a clear funding condition, and a vote." If you want to win this argument, learn the Printz case better than the other side does. When they cite it, you can say you agree with the principle, and then show them what it does not cover. That is how you persuade a skeptic instead of just entertaining your friends. The same federalism that protects a sanctuary city also protects the people in the country from a federal government that forgets its limits.

The bottom line

• The sanctuary argument has real constitutional roots: New York v. United States (1992), Printz v. United States (1997) and Murphy v. NCAA (2018) say Washington cannot commandeer state and local officers.
• Detainers are requests, so declining to honor them is lawful. Obstructing federal agents, or hiding specific people from them, is not protected by the Tenth Amendment.
• Section 1373 on information sharing and section 1324 on harboring are real statutes, but courts have not settled how far either reaches, so check the latest rulings before you quote them.
• Conditions on federal grants are lawful under South Dakota v. Dole when Congress writes them clearly. Ask your representatives to write them, instead of expecting a memo to do it.
• Remember that cities answer to their state legislatures. If your city has a policy you dislike, your state capital is where the lawful lever is.