Donald Trump has threatened to use the 19th-century Insurrection Act to send federal troops into Minnesota, as protests continue in the Minneapolis area. The Associated Press said the law allows a president to use the armed forces inside the country and that Trump’s approach would mark a rare modern use of a statute that has been invoked more than two dozen times overall.

The AP report said Trump would be the only commander in chief to use the Insurrection Act to quell protests that began after actions by federal agents he had already sent to the area. It said videos and accounts described violence involving federal agents, including a shooting that resulted in the death of a U.S. citizen identified as Renee Good.

Legal experts cited by AP said the threatened use of the act does not fit past patterns. Joseph Nunn, a lawyer with the Brennan Center for Justice’s National Security Freedom Program, warned that using the law in this context would be an unprecedented abuse, saying, “Esto constituiría un abuso flagrante de la Ley de Insurrección como nunca hemos visto antes” and that “No se ha cumplido ninguno de los criterios.”

AP said Trump’s position is that Minnesota officials and citizens are obstructing federal enforcement of immigration law and the work of agents including ICE and CBP. Nunn said ICE has legal authority to enforce federal immigration laws, but argued that “lo que están haciendo es una especie de comportamiento violento e ilegal” and that it “fomenta la situación” that Trump wants to repress. He also said, “No pueden crear una crisis intencionalmente, y luego dar un giro para reprimir,” and tied the constitutional duty to carry out laws “de buena fe” to how the president should use the Insurrection Act and his immigration authority.

The AP description of how the Insurrection Act has historically been used emphasizes different triggers. It said federal forces are typically called when local authorities request help to quell widespread violence before Washington intervenes. It also said presidents have acted without a local request more often when the goal was to enforce the rights of people threatened or not protected by state and local governments, and it cited open insurrection scenarios like the Confederacy during the Civil War.

The article traced the law’s origins to the early republic. It said George Washington promulgated an initial version in 1792 authorizing him to mobilize state militias when “las leyes de Estados Unidos sufran oposición o se obstruya su ejecución,” and that Washington and John Adams used the law to suppress citizen revolts against taxes. The report said Congress expanded the law in 1807 and reaffirmed presidential authority to counter “insurrección u obstrucción” affecting U.S. laws, while Nunn said early statutes reflected a “tradition angloamericana contra la intervención militar en asuntos civiles,” with exceptions only as a last resort.

AP said legal and military experts argue that constitutional and historical comparisons to Minneapolis do not support the threatened move. It said courts have blocked some of Trump’s efforts to deploy the National Guard, and noted that Trump’s argument for federal troops under the Insurrection Act would be that he does not need a state’s permission to send them.

The report described how the Civil War era reshaped presidential deployment. It said Abraham Lincoln argued in 1861 that southern states could not legitimately secede and persuaded Congress to grant express authority to deploy federal soldiers without asking in states he considered part of the Union. It said Nunn characterized later uses as still requiring a local request or another trigger Congress added after the Civil War to protect individual rights, and it cited Ulysses S. Grant’s use of such authority to send soldiers against the Ku Klux Klan and other white supremacists who ignored the 14th and 15th amendments and civil-rights laws.

In its examples of later deployments, the AP said the postwar period saw federal involvement during outbreaks tied to labor and immigration. It also said presidents used the strategy again during the civil-rights era, including Franklin Roosevelt’s sending of 6,000 soldiers to Detroit after racial disturbances that began with attacks on Black residents, with local officials requesting help. It said Nunn linked some later deployments to the role of local law enforcement in amplifying violence.

The AP also outlined well-known episodes in the 1950s and 1960s. It said Dwight Eisenhower used the act to impose integration at Little Rock Central High School in Arkansas, and that John F. Kennedy sent troops to the University of Mississippi after disturbances tied to James Meredith’s admission, with later deployment aimed at preventing violence during incidents associated with George Wallace’s resistance to integration at the University of Alabama. It said Lyndon Johnson protected the 1965 Selma-to-Montgomery voting-rights march after Wallace’s forces attacked protesters during their first peaceful attempt, and it said Johnson also sent troops in 1967 and 1968 after clashes between residents and police intensified in several cities.

Finally, the AP said the last time the Insurrection Act was invoked was in 1992 in Los Angeles. It said those disturbances followed a jury’s failure to convict four white police officers despite a video showing an attack on Rodney King, and it said California Gov. Pete Wilson requested help from President George H.W. Bush. The report said Bush authorized about 4,000 soldiers, then directed the Justice Department to open a civil-rights investigation after expressing public dissatisfaction with the verdict, and it said two of the Los Angeles officers were later found guilty in federal court.