Tensions escalated sharply across the United States as President Donald Trump’s administration ordered the deployment of U.S. Marines to Los Angeles, a decision that has sparked legal challenges, widespread protests, and fierce pushback from local and state officials.

Approximately 700 Marines from Southern California bases were en route to Los Angeles by Monday night, marking a rare military deployment to a major U.S. city to support law enforcement amid civil unrest. The White House stated the move was intended to bolster federal efforts during sweeping immigration raids, which have ignited protests nationwide and intensified political divisions.

The deployment — intended to secure federal facilities and personnel until 4,000 National Guard troops arrive — was made without a request from California or Los Angeles leaders. In response, California Governor Gavin Newsom filed a lawsuit on Monday, arguing the federal intervention breaches constitutional boundaries and undermines state authority.

“This is a city of immigrants,” said Los Angeles Mayor Karen Bass, denouncing the raids and the federal response.

But Homeland Security Secretary Kristi Noem dismissed such opposition and defended the administration’s actions, pledging an even more aggressive crackdown.

“We conducted more operations today than we did the day before and tomorrow we are going to double those efforts again,” she told Fox News’ Hannity.

• California defies Trump as Marines deploy amid sweeping immigration crackdown

“The more that they protest and commit acts of violence against law enforcement officers, the harder ICE is going to come after them.”

Despite not invoking the Insurrection Act, the president exercised his powers as commander in chief to order the military deployment. Experts noted that while military aid during national disasters is more common, domestic use of troops during protests remains highly unusual and controversial.

Protests in Los Angeles entered their fourth day on Monday, with demonstrators gathering outside a federal detention facility. The crowd, chanting “free them all” and waving Latin American flags, was eventually dispersed by police using tear gas and “less-lethal” munitions. Dozens of arrests were reported.

California’s top leaders expressed alarm over the federal show of force.

“The president is forcibly overriding the authority of the governor and mayor and using the military as a political weapon,” said Senator Jack Reed, a leading Democrat on the Senate Armed Services Committee.

“This unprecedented move threatens to turn a tense situation into a national crisis.”

Reed added, “Since our nation’s founding, the American people have been perfectly clear: we do not want the military conducting law enforcement on U.S. soil.”

Trump, however, signaled he was prepared to go further, endorsing a suggestion by border advisor Tom Homan to arrest Governor Newsom for alleged obstruction.

“I would do it if I were Tom. I think it’s great,” Trump said.

Governor Newsom called the deployment “an unmistakable step toward authoritarianism,” reaffirming his position that states must control National Guard operations within their borders.

Meanwhile, protests erupted in at least nine other cities, including New York, San Francisco, Philadelphia, and Austin, where police clashed with demonstrators and made multiple arrests. The response in Los Angeles extended into the Little Tokyo district, where clashes between protesters and heavily armed officers unfolded into the evening. Loud flash-bangs and tear gas echoed through downtown streets, rattling residents and tourists alike.

For many protesters, the crackdown is personal.

“What is happening affects every American, everyone who wants to live free, regardless of how long their family has lived here,” said Marzita Cerrato, 42, a first-generation immigrant.

Federal officials revealed that recent operations have resulted in a dramatic surge in arrests — around 2,000 per day — compared to a daily average of 311 under the Biden administration.

As political leaders clash over the legality and morality of the military involvement, Americans across the country face a growing national divide over immigration, states’ rights, and the role of federal power in civilian life.

Homeland Security Secretary Noem reinforced her department’s stance during the Fox interview.

“They are not a city of immigrants. They’re a city of criminals,” she said of Los Angeles, prompting further backlash from local leaders and civil rights groups.