A demonstrator wearing an inflatable Capybara costume stands outside of the U.S. Immigration and Customs Enforcement (ICE) headquarters, as police work to disperse the crowd to clear traffic driving into the ICE building, during a protest, in south Portland, Oregon, U.S., October 6, 2025. REUTERS/Carlos Barria
Activists wave to vehicles from an overpass on the Henry Hudson Parkway behind a sign reading "No Troops in Our Cities" after U.S. President Donald Trump said on Monday that the U.S. military might deploy to Chicago and other U.S. cities, in upper Manhattan, New York City, U.S., October 7, 2025. REUTERS/Mike Segar
Law enforcement officers detain a protester outside the U.S. Immigration and Customs Enforcement (ICE) headquarters in south Portland, Oregon, U.S., October 5, 2025. REUTERS/Carlos Barria

By Emily Schmall

CHICAGO (Reuters) -Donald Trump's threat to invoke a federal anti-insurrection law to expand his deployment of military personnel to U.S. cities has intensified his legal battle with Democratic-led cities over presidential authority, as hundreds of National Guard troops from Texas on Tuesday prepared to patrol the streets of Chicago.

The president told reporters on Monday he would consider utilizing the Insurrection Act, a law enacted more than two centuries ago, to sidestep any court rulings restricting his orders to send Guard troops into cities over the objections of local and state officials.

"We have an Insurrection Act for a reason," Trump said. "If people were being killed and courts were holding us up, or governors or mayors were holding us up, sure, I'd do that."

The law, which gives the president authority to deploy the military to quell unrest in an emergency, has typically been used only in extreme cases, and almost always at the invitation of state governors. The act was last invoked by President George H.W. Bush during the Los Angeles riots of 1992.

INSURRECTION ACT EXCEPTION TO RULE

Under federal law, National Guard and other military troops are generally prohibited from conducting civilian law enforcement. But the Insurrection Act operates as an exception to that rule and would give troops the power to directly police and arrest people.

Using the act would represent a significant escalation of Trump's campaign to deploy the military to Democratic cities, an extraordinary assertion of presidential power. Last week, in a speech to top military commanders, Trump suggested using U.S. cities as "training grounds" for the armed forces, alarming Democrats and civil liberties groups.

Trump has ordered Guard troops to Chicago, the third-largest U.S. city, and Portland, Oregon, following his earlier deployments to Los Angeles and Washington, D.C. In each case, he has done so despite staunch opposition from Democratic mayors and governors, who say Trump's claims of lawlessness and violence do not reflect reality.

In Chicago and Portland, protests over Trump's immigration policies had been largely peaceful and relatively limited in size, according to local officials.

Since Trump surged federal agents to the Chicago area last month, residents have responded with mostly small demonstrations. In most of Chicago, people have commuted to work, gone to the theater and flocked to beaches to enjoy unseasonably warm weather in a city where violent crime has fallen sharply - far from the "war zone" conditions Trump has described. Protests have been much less disruptive than the unrest in 2020 triggered by the death of George Floyd, an unarmed Black man, at the hands of Minneapolis police officers.

The most regular demonstration has taken place outside an immigration processing facility in the Broadview suburb, where up to several dozen people have been engaged in increasingly violent standoffs with federal immigration officers, who have fired tear gas and rubber bullets from the roof of the facility at protesters.

Several people, including at least one reporter, have been arrested, and dozens of people have been injured by the agents' chemical munitions.

GOVERNOR ALLEGES TRUMP USING GUARD AS PROPS

Illinois Governor JB Pritzker, a Democrat, accused Trump of intentionally trying to foment violence in Chicago, which the president could then use to justify further militarization.

"Donald Trump is using our service members as political props and as pawns in his illegal effort to militarize our nation's cities," Pritzker told reporters on Monday.

Illinois and Chicago sued the Trump administration on Monday, seeking to block orders to federalize 300 Illinois Guard troops and send 400 Texas Guard troops to Chicago. During a court hearing, Justice Department lawyers told a federal judge that hundreds of Texas Guard troops were already in transit to Illinois.

The judge, April Perry, permitted the deployment to proceed for now but ordered the U.S. government to file a response by Wednesday.

Separately, a federal judge in Oregon on Sunday temporarily blocked the administration from sending any National Guard troops to police Portland, the state's largest city.

National Guard troops are state-based militia who normally answer to the governors of their states and are often deployed in response to natural disasters.

During Trump's deployments to various cities, the Guard has been limited to protecting federal agents and property, though the Defense Department has said troops have the authority to detain people temporarily to prevent immediate harm.

A federal judge ruled last month that troops in Los Angeles overstepped their authority by controlling crowds and blocking traffic. The Trump administration has argued those actions were legal to protect federal agents conducting immigration raids and has appealed the decision.

Any effort by Trump to invoke the Insurrection Act would also likely face legal challenges. The law has rarely been interpreted by the courts, but the Supreme Court has ruled that the president alone can determine if the act's conditions have been met. Those conditions include when the U.S. government's authority is facing "unlawful obstructions, combinations or assemblages or rebellion."

The act, a version of which was first enacted in 1792, has been used by past presidents to deploy troops within the U.S. in response to crises such as the 1794 Whiskey Rebellion and the rise of the Ku Klux Klan after the American Civil War.

But the last time another president deployed the National Guard in a state without a request from the governor was 1965, when President Lyndon Johnson sent troops to protect civil rights demonstrators in Montgomery, Alabama.

(Reporting by Emily Schmall in Chicago; Additional reporting by Tom Hals, Jan Wolfe and Dietrich Knauth; Writing by Joseph Ax; Editing by Frank McGurty, Nick Zieminski, Rod Nickel)