Illinois leaders went to court Monday to stop President Donald Trump from sending National Guard troops to Chicago, escalating a clash between Democratic-led states and the Republican administration during an aggressive immigration enforcement operation in the nation’s third-largest city.

The legal challenge came hours after a judge blocked the Guard's deployment in Portland, Oregon.

The Trump administration has portrayed the cities as war-ravaged and lawless amid the government's crackdown on illegal immigration. Officials in Illinois and Oregon say military intervention isn’t needed and that federal involvement is inflaming the situation.

Elizabeth Goitein, a National Security Law Expert with the Brennan Center for Justice, said there are now four lawsuits total that are "pushing back on the grounds that these deployments are not only out of step with traditional and principles, they are illegal."

U.S. District Judge Karin Immergut on Sunday granted a temporary restraining order sought by Oregon and California barring the deployment of Guard troops to Oregon from any state and the District of Columbia.

Immergut, who was appointed by Trump during his first term, seemed incredulous that the president moved to send National Guard troops to Oregon from neighboring California and then from Texas on Sunday, just hours after she had ruled against it the first time.

“Aren’t defendants simply circumventing my order?” she said. “Why is this appropriate?”

Since Trump's second term, there have been protests outside the city's ICE facility. Demonstrations peaked mid-June, when Portland Police declared a riot. Since then, nightly protests have been small, attracting a few dozen people — until Trump ordered the National Guard to deploy.

Over the weekend, larger crowds gathered outside the facility and federal agents fired tear gas, deployed pepper spray and made several arrests.

Most violent crime around the U.S. has actually declined in recent years, including in Portland, where homicides from January through June decreased by 51% to 17 this year compared to the same period in 2024, data shows.

Since the start of his second term, Trump has sent or talked about sending troops to 10 cities, including Baltimore; Memphis, Tennessee; the District of Columbia; New Orleans; and the California cities of Oakland, San Francisco and Los Angeles.

Last month a federal judge ruled President Donald Trump’s administration “willfully” broke federal law by sending National Guard troops to the Los Angeles area in early June after days of protests over immigration raids.

In the 52-page ruling, U.S. District Judge Charles Breyer in San Francisco noted Trump and Defense Secretary Pete Hegseth have stated their intention to deploy National Guard troops to other cities across the country, including Oakland and San Francisco, and that raises concerns they are “creating a national police force with the President as its chief.”

California sued over the deployment of troops, saying it violates the Posse Comitatus Act, a 1878 law that prohibits military enforcement of domestic laws.

Lawyers for the Trump administration argued the Posse Comitatus Act doesn’t apply because the troops were protecting federal officers, not enforcing laws, and that the president had the authority to call on the troops.

Trump federalized members of the California National Guard under section 12406 of Title 10, which allows the president to call the guard into federal service when the country “is invaded,” when “there is a rebellion or danger of a rebellion against the authority of the Government,” or when the president is otherwise unable “to execute the laws of the United States.”

The deployment appeared to be the first time in decades that a state’s national guard was activated without a request from its governor, a significant escalation against those who have sought to hinder the administration’s mass deportation efforts.

Thousands of protesters took to the streets in response, blocking off a major freeway and setting self-driving cars on fire as law enforcement used tear gas, rubber bullets and flash bangs to control the crowd.

"It really has to be a very high level of violence or obstruction before it's appropriate to invoke this law," Goitein told the AP.

"It can't just be the case that there are some incidents of protesters breaking the law, throwing things, you know, obstructing vehicles. That's not sufficient, because that is the kind of thing that civilian authorities can and do handle all the time."