by Andrea Katz, Washington University in St. Louis, [This article first appeared in The Conversation, republished with permission]

A federal judge heard arguments on Jan. 26, 2026, as the state of Minnesota sought a temporary restraining order to stop the Trump administration’s immigration enforcement operation in the state. The administration has sent some 3,000 immigration agents to Minnesota, and attorneys for the state have argued, in part, that it amounts to an unconstitutional occupation, on 10th Amendment grounds. Alfonso Serrano, a politics editor at The Conversation U.S., spoke with Andrea Katz, a law scholar at Washington University in St. Louis, about the Minnesota lawsuit and its possible legal implications.

What’s the legal issue at stake in this court case?

In Minnesota v. Noem, attorneys for the state are arguing that the federal government is acting illegally by intruding on a sphere of state power (the police power). They’re claiming violations of the 10th Amendment, which is this idea that under the U.S. Constitution, states are reserved powers that existed before the Constitution was drafted, powers that are not delegated to the federal government.

They’re also making this rather new claim under what’s called the equal sovereignty principle, which is that states all have to be treated equally by the federal government. There’s also a First Amendment claim, and an Administrative Procedure Act claim, which is that the government is acting illegally in an arbitrary and capricious way. I think the 10th Amendment arguments are ones that I would say are kind of unprecedented, rather untested waters.

On that note, when does a federal law enforcement response cross the line and violate the 10th Amendment? Is there precedent for this?

The question you just posed is one that the district judge, Kate M. Menendez, seems to be nervous about having to hear. This is essentially asking a federal judge to sift into different buckets that which is federal power and that which is state power. And I can say there’s not a lot of case law on this issue.

The most filled-out doctrine under the 10th Amendment is the anti-commandeering doctrine. It holds that the federal government cannot use the state government as a sort of puppet. The federal government can’t use state officers forcibly against the state’s will to enforce the law. Now that is not, strictly speaking, what’s going on here, because Minnesota is complaining about the presence of federal agents enforcing the laws in ways that it thinks are illegal.

And so it seems to me that the 10th Amendment has been most developed in this area that Minnesota is not touching on, and so for that reason, I think their invocation of it is pretty unusual. They’re essentially claiming that the 10th Amendment protects their police powers and that the federal government is intruding on that. I think that’s a novel argument in court, and my suspicion is that it is not likely to be a winning argument in court.

The Trump administration has dismissed the state’s legal theory, saying the president is acting within his authority, correct?

Yeah, I think that’s correct. Again, I want to make clear that Minnesota has made many arguments against the Trump administration, and I’m just focusing on the merits of this 10th Amendment argument.

There was a sort of undeveloped strand of cases in the mid-20th century where the Supreme Court tried to develop this idea of core state powers. And so it said the federal government couldn’t act in a way that violated a state’s core powers, like where to put your state capital, or control over natural resources, or defining salaries for state government employees. The court said these are core state powers.

But then in a famous case called Garcia v. San Antonio Metropolitan Transit Authority, in 1985, the court overruled itself and said – and this is still where we are – federal courts cannot be in the business of defining what constitutes a core state power. It’s too open-ended, undefined. It’s a political inquiry. It’s not something that’s appropriate for a judge.

And so I think on this 10th Amendment argument, Minnesota is essentially asking the courts to revive this core state powers doctrine, which I think the court is unlikely to do.

What repercussions could the judge’s ruling have?

Minnesota has already filed, in a case called Tincher v. Noem, a more conventional set of claims, which is that ICE agents broke the law, are violating rights, acting in excess of their authority. They have already gotten preliminary relief on this first set of claims, although Judge Menendez’s order is now on hold, pending appeal before the 8th Circuit court.

That is different from this 10th Amendment claim. In the 10th Amendment argument, one of the arguments that Minnesota has made is the equal sovereignty principle. The equal sovereignty principle was articulated in the 2013 case, Shelby County v. Holder. This is the famous case where the Supreme Court struck down an important part of the Voting Rights Act that prevented Southern states from restricting the vote, apparently on the basis of race. In Shelby County, the court said that the Voting Rights Act, which subjected certain states with a pattern of racial discrimination on the vote to a preclearance process where the federal government had to approve their laws before they passed them, treated different states differently.

Of course, in that case, the federal government said those are states that have a history of discrimination, so the federal government was justified in treating them differently.

But Chief Justice John Roberts, who wrote the Shelby County opinion, said the 10th Amendment means that the government can’t treat different states differently.

Now it’s not a well-regarded doctrine, so it’s kind of shocking that Minnesota is invoking it here. For one reason, the equal sovereignty principle has not been well developed since Shelby County. The second reason it would be a big deal – quite shocking to me, if the judge enforced it – is that Shelby County was talking about legislation that treated different states differently.

If we pass a rule where the executive branch can’t treat different states differently, you’re essentially denying the existence of discretion in enforcement, which is very quintessentially an executive power, right?

It could, for example, lead to states saying that federal agents can’t come in to help people in a natural disaster. So again, I think this argument, like the rest of the 10th Amendment arguments, suffers from being undeveloped in the case law and potentially carrying a risk of kneecapping the federal government’s ability to enforce the law, which sometimes does, for totally good-faith reasons, require treating different states differently.

Any final thoughts?

The first Trump administration was highly disorganized and didn’t take concerted action for a while. The second Trump administration was the precise opposite of that. They acted quickly and in a very organized fashion, pushing power as far as it can go in a number of agencies.

And I think the question this gets back to is how the federal courts have reacted to this barrage of executive orders, of new applications of old laws, of new forms of government power exercised in a way that threatens federalism.

The federal courts usually grant deference to the president when the government issues statements in the context of litigation. Court doctrine is to defer to those statements as being entitled. It’s a presumption of regularity, of accuracy. And I think we’re already seeing in the district courts some suspicion by the judges of the government’s version of things.

To me, this is sort of a brave new world, whether we’re going to see courts relax their deference toward the executive branch. And I mean, we are in kind of a brave new world. We have videos all over the internet showing the facts of the Alex Pretti shooting. But I just want to note that, from a separation of powers point of view, it’s very interesting to see federal judges seeming to distrust official accounts of events from the executive branch. I think this is an area in which the doctrine seems to be moving, and we’re watching it in real time.

Andrea Katz, Associate Professor of Law, Washington University in St. Louis

This article is republished from The Conversation under a Creative Commons license. Read the original article.