The Tenth Amendment to the U.S. Constitution is so short and self-evident that you don’t need a law degree to understand it, or a judge to explain it to you: “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.” That language had real teeth during Donald Trump’s first Presidency, as states, cities, and localities invoked it to stop his abuse of immigration laws, of the purse strings that belong to Congress, and of their own authority over their affairs and general welfare. This fight against government overreach has continued well into Trump’s second term. “Here we are again,” William Orrick, a senior federal-district judge in San Francisco, wrote in a recent opinion barring the Trump Administration from withholding funding that Congress had already allocated to state and local authorities for policing and other prerogatives. (He made a similar ruling during the first Trump Presidency.) The Administration’s actions, Orrick wrote, in April, “violate the Tenth Amendment because they impose coercive condition[s] intended to commandeer local officials into enforcing federal immigration practices and law.”
For the past two months, in a courtroom not far from Orrick's, another senior U.S. district judge, Charles Breyer, has been grappling with whether the Tenth Amendment and federal law provide “a limiting principle” to a President who wills local problems into national ones. In June, as Los Angeles residents protested how Immigration and Customs Enforcement was disrupting people’s lives and work, Trump’s response was to send in backup from California’s National Guard, the largest such force in the country. “To the extent that protests or acts of violence directly inhibit the execution of the laws, they constitute a form of rebellion against the authority of the Government of the United States,” a Presidential memorandum to Pete Hegseth, the Defense Secretary, said. Governor Gavin Newsom and the state of California sued almost immediately, leading to the case known as Newsom v. Trump.
Judge Breyer, the younger brother of the retired Supreme Court Justice Stephen Breyer, has a problem with the word “rebellion”; he underlined it in his first opinion in the case. The word appears in the Constitution five times—four of them in the Fourteenth Amendment, the centerpiece of Reconstruction and Black equality after a real rebellion of states that wanted neither. The other appearance is in Article I, which grants Congress alone the power to suspend the writ of habeas corpus—the very mechanism that Stephen Miller and Kristi Noem have claimed grants the Administration power to detain and disappear people from this country. The word also shows up in the law that Trump invoked to federalize the California Guard. “Is it a ‘rebellion’ because the President says it is a ‘rebellion’?” Breyer asked during the trial for Newsom v. Trump, which lasted three days and ended last week.
At the outset of the case, and less than a week after Trump’s deployment of the California National Guard, Breyer had written an opinion declaring Trump’s actions illegal—“both exceeding the scope of his statutory authority and violating the Tenth Amendment to the United States Constitution.” Trump, he wrote, “must therefore return control of the California National Guard to the Governor of the State of California forthwith.” Yet almost as quickly as he ruled, a panel of the U.S. Court of Appeals of the Ninth Circuit, which included two judges appointed by Trump during his first term, pumped the brakes on Breyer’s constitutional pronouncement and ruled for the President on a different ground—namely, that his federalization of the California National Guard complied with a statute that allows him to do just that.
Indeed, in Section 12406 of Title 10, which governs the armed forces, Congress decided to delegate to the President its own constitutional authority to call on “the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions.” Under this statute, if the President “is unable with the regular forces to execute the laws of the United States”—or to quell imminent foreign invasions or domestic rebellions—he may federalize any one state’s National Guard to aid him in those efforts. But can the President trigger the statute whenever he feels like it, and for however long? Rather than drawing a line in the sand, the appeals court leaned on precedents establishing that the President remains “the sole and exclusive judge” of facts on the ground—the precondition for calling in the military on a state’s own citizens. As the Ninth Circuit explained, “our review of that decision must be highly deferential.”
Must be? If that’s true, then there’s no stopping Trump from federalizing the National Guard in all fifty states. In the District of Columbia, where federal law gives the President significant leeway, Trump has already mobilized the D.C. National Guard, after declaring an “epidemic of crime in our Nation’s capital.” Newsom v. Trump matters because the case, even as limited by Trump’s own judges to a statutory dispute, may yet seal the fate of the delicate compact the Constitution sets out between the national government, the states, and the rest of us. Can a President break that compact, without consequence, usurping police powers that were never his to begin with?
In bench trials, which happen without a jury, judges act as finders of fact and law. At the beginning of the bench trial in Newsom v. Trump, Breyer announced that the “single factual issue” before him was one that the Ninth Circuit did not address, and that California had also raised in its lawsuit: whether the Trump Administration had violated the Posse Comitatus Act of 1878. In other words, was there sufficient evidence that the federal government had relied on the California National Guard as a “posse,” for the purpose of executing domestic laws, much as local police would? The Posse Comitatus Act, last updated in 2021 for reasons that will become immediately clear, is one sentence: “Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army, the Navy, the Marine Corps, the Air Force, or the Space Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.”
Traditionally understood as a ban against standing armies’ engaging in civilian law enforcement, one of the concerns expressed in the Declaration of Independence, the Posse Comitatus Act has taken on a life of its own within the military, becoming embedded in many policies and practices. Informing basic training, various directives, and even legal advice, the act serves as a sort of compass guiding military behavior. Because the act is written as a criminal prohibition, and only the federal government can prosecute violations of federal criminal law, the statute poses a few legal hurdles for Breyer: Can California sue under a statute that only the U.S. government can enforce? And, since the remedy for violations of this criminal law is a fine or imprisonment, can you invoke the statute in a civil suit to enjoin the Administration from the unlawful domestic deployment of troops? And, finally, didn’t Congress, in allowing the President to federalize the National Guard “to execute the laws of the United States,” give the executive branch an exception from the ban on engaging in general law-enforcement activities?
These are all legal, not factual, questions that Breyer will have to resolve in due course. (He has yet to issue a ruling.) But the facts that he elicited during the trial, some of which unfolded in real time, may help him reach a conclusion. William Harrington—an Army deputy chief of staff who wrote reports on the activities of Task Force 51, the four-thousand-person unit, plus seven hundred Marines, deployed to the Los Angeles area—testified that the Posse Comitatus Act was on his mind on June 7th, the day Trump directed Hegseth to mobilize the National Guard. During a briefing with task-force leadership that day, Harrington said he brought up the act, and that everyone in the room understood that it applied, and thus that the California National Guard, once federalized and deployed, could not engage in law-enforcement activities.
During the trial, the California attorney general’s office tried to create, as one Politico reporter put it, a split-screen moment with the federal takeover playing out in Washington, D.C. Jane Reilley, the California lawyer examining Harrington, pulled a question straight from the day’s headlines: Are you aware that the Secretary of Defense announced the deployment of National Guard troops in Washington, D.C.? Federal prosecutors objected loudly, citing irrelevance. But Breyer allowed the question. After all, part of his job, if he finds that the Posse Comitatus Act was violated, is to craft injunctive relief—a remedy to prevent future violations, he explained. And, surely, understanding how the Administration is using the National Guard in other places would help the judge with his fact-finding. “No, I was not aware,” Harrington replied.
Over the government’s objections, a statement from Hegseth from that same morning, during the deployment of troops in D.C. was played in open court. “This is nothing new for D.O.D.,” Hegseth said from the White House briefing room, flanked by Trump, Attorney General Pam Bondi, and the newly minted top federal prosecutor in the District of Columbia, the former Fox News personality Jeanine Pirro. “In Los Angeles, we did the same thing—working with the California National Guard, working with ICE officers.” (Also admitted into court was a video of Trump, from the same briefing, suggesting that other cities, including Baltimore and Oakland, were up next.)
Even more dramatic was the testimony of Major General Scott M. Sherman, who was in command during the Los Angeles mobilization. In one episode in July that drew widespread condemnation from Angelenos, immigration agents, riding in armored vehicles and on horseback, accompanied by the National Guard, descended on MacArthur Park—an ostentatious show of force that the Los Angeles Times likened to “a Hollywood movie.” Sherman confirmed that the scene, code-named Operation Excalibur, was entirely rehearsed—and that, although it had originally been planned for Father’s Day weekend, he had expressed concern that the park would be too crowded, and so it was moved to July 7th. “We assessed that there could be a large amount of people in the park, which could quickly overwhelm Border Patrol,” Sherman testified. Hegseth himself approved the stunt; there have been no reports of any arrests that day.
One moment during Sherman’s testimony illustrated the rift that exists between how the military perceives its deployment, and how immigration agents, who are more closely aligned with Trump’s goals, perceive theirs. During testimony about the MacArthur Park operation, Sherman was asked whether Gregory Bovino, a brash Customs and Border Protection sector chief, questioned Sherman’s loyalty to the United States because of his raising concerns about timing. The Justice Department objected, but, once again, it was overruled, with Breyer suggesting that calling out a leader’s exercise of “military judgment” as disloyal is entirely relevant to the main question in the case: whether troops were respecting the civil-military divide embodied in the Posse Comitatus Act. Once cleared to answer, Sherman gave a muted yes.
Bovino, for his part, has continued to play for the cameras in downtown Los Angeles. Last Thursday, he and other federal immigration agents showed up outside a news conference by Newsom, during which the governor hoped to lay out a plan to counteract another Trump power grab—his push for new congressional maps in Texas. Los Angeles’s mayor, Karen Bass, called this unannounced show of force, not unlike others that have rattled L.A. communities, “a provocative act”; it claimed one casualty, an unsuspecting delivery driver whom immigration authorities arrested at the scene. “We’re glad to be here,” Bovino told a local television reporter. “We’re not going anywhere.”
It is hard to divorce the technical legal questions in Newsom v. Trump from the sights and sounds, all admitted into evidence, confirming that the President’s commandeering of civilian and military personnel for immigration enforcement was designed to strike fear in migrant workers and their communities. Much of the Administration’s crackdown in California has also been trained on people who simply look like they might be immigrants, who live and work in areas where employing immigrants is commonplace, who speak Spanish, or who congregate where immigrants seek out work. A separate legal battle, waged by immigrants’-rights advocates and day laborers, now pending at the Supreme Court, will soon determine whether immigration agents can be prevented, as they were by one judge last month, from racially profiling and sweeping up immigrant workers simply going about their daily lives in seven counties in the federal district that includes Los Angeles.
Many of those sweeps haven’t required the assistance of the California Guard. But the state’s case against the Trump Administration rests on three discrete operations, each of them more than fifty miles from Los Angeles, where the Guard was involved, and where they were not merely providing “protective activities” to agents being stymied from enforcing immigration laws, nor protecting federal buildings—the original rationale for their mobilization. Rather, as California argued, they were called on to add to immigration agents’ numbers—to act as a “force multiplier” in situations where the threat to federal personnel or property was minimal or nonexistent, and where the targets, much as they were in the city proper, were workers who posed no risk of harm to anyone.
In all three operations, in the localities of Mecca, Camarillo, and Carpinteria, hundreds of troops were called in to support D.H.S. agents conducting highly targeted, planned raids aimed at cannabis farms and farmworkers. These raids had all the hallmarks of a law-enforcement operation: federal agents had obtained search warrants to enter the premises; troops set up security perimeters around the sites and on public roads, which had the effect of preventing the movement of civilian traffic; and hundreds of migrant workers, some of whom left children behind, were arrested. (One farmworker, Jaime Alanís García, died after he fell from the roof of a greenhouse at one of the raided farms.) Sherman, who, during the trial for Newsom v. Trump, was shown images taken during one of the operations, could not explain what his own service members were doing. At times, he and other government witnesses could hardly tell U.S. troops apart from federal law enforcement.
After California rested its case, on the first day of trial, Sherman returned to the stand on the second day, this time as the Justice Department’s only witness, largely to clean up his prior testimony and to try to persuade Judge Breyer that Task Force 51 was doing everything by the book. Sherman may have muddied things more when he testified that his force operated under a “constitutional exception” allowing them to undertake run-of-the-mill law-enforcement activities—which would violate the Posse Comitatus Act—because Trump’s federalization order assumes that the President can’t enforce the law in the usual way, and thus needs the military to help him do it. “That’s the legal advice I received,” Sherman said.
