Defense Secretary Pete Hegseth told lawmakers Tuesday that he and President Donald Trump have the power to send National Guard and active-duty troops anywhere in the country to ensure Immigration and Customs Enforcement agents can enforce the law, an assertion that -- if carried out -- would open the door to a historic clash between Trump and Democratic governors.
"We believe that ICE, which is a federal law enforcement agency, has the right to safely conduct operations in any state, in any jurisdiction in the country," Hegseth told the House Appropriations Defense subcommittee.
"ICE ought be able to do its job, whether it's Minneapolis or Los Angeles," he added.
Hegseth's testimony before a House panel came as some 4,800 National Guard and Marines were en route to Los Angeles for a 60-day deployment after protestors clashed with law enforcement, setting cars on fire and spraying graffiti on buildings.
President Donald Trump also opened the door for possible military deployments elsewhere, telling reporters on Tuesday that if protests break out in other states "they will be met with equal or greater force."
The move to call in U.S. troops, including 700 Marines, ignored objections by state authorities and was sharply criticized by Democratic lawmakers and California Gov. Gavin Newsom, who called the deployment inflammatory and warned it would only escalate tensions.
At Tuesday's hearing, Rep. Betty McCollum of Minnesota, the top Democrat on the House subcommittee, called the decision "premature" and "downright escalatory." She said Marines aren't suited for a domestic mission in which they could be asked to use their combat training and firepower, typically reserved for foreign adversaries, on Americans.
"Active-duty military has absolutely no role in domestic law enforcement, and they are not trained for those missions. I ask you, Mister secretary, and I ask the president, follow the law," she said.
The Pentagon's top acting budget official, Bryn Woollacott MacDonnell, estimated the deployment would cost $134 million and said the money would be pulled from existing operations and maintenance accounts.
The Trump administration said the troops are being used under a legal authority known as Title 10 of the U.S. Code, which allows the president to deploy military forces to protect federal buildings and personnel in cases of "a rebellion or danger of rebellion against the authority of the Government of the United States" or when "the President is unable with the regular forces to execute the laws of the United States."
U.S. officials said the "rules for force" for such an engagement would restrict troops from patrolling U.S. streets or helping law enforcement arrest protestors. Troops would carry guns and ammunition separately for use only in self-defense and to protect federal property.
But experts say the rules of protecting federal buildings and personnel could get murky if service members are asked to protect ICE personnel during an immigration raid or if protestors attack buildings.
Rachel VanLandingham, a professor at Southwestern Law School in Los Angeles and former chief legal advisor to U.S. Central Command, said she is skeptical that Marines who are trained to fight and win foreign wars are sufficiently trained to police Americans.
"Protection means you protect by using force. So, what kind of force are we using? What kind of forces are they trained to use?" she told ABC's "Start Here" podcast.
"You fight like you train," and "they have never trained to be working with the National Guard in this capacity," she added.
Marine Corps Commandant Gen. Eric Smith said that the 700 Marines were trained in crowd control as part of their standard annual training protocols. He noted the Marines were equipped with shields and batons.
"I would say that all Marines are trained in crowd control, embassy reinforcement, etc. So, this is part of their training," Smith told the Senate Armed Services Committee.
When asked how much training in crowd control they received, Smith said he believed it was "in excess of two hours."
Sen. Elissa Slotkin, a Michigan Democrat, said she was skeptical that amount was adequate, noting police forces typically receive 600 hours of crowd control training by comparison.
"I don't question that these things in LA have gotten violent. That's not my question, and I condemn it. I'm worried about the reputation of the US military in the United States of America," she said, adding that Marines were "designed" to be lethal.
"The idea that an apolitical military, which we all should cherish and value, are now going to be thrown into a situation" isn't right, she said. "We don't need them to create a dramatic story."
Still in question is whether Trump is considering to escalate the situation by invoking the Insurrection Act, an 1807 law that says the president can call on a militia or the U.S. armed forces if there's been "any insurrection, domestic violence, unlawful combination, or conspiracy" in a state that "opposes or obstructs the execution of the laws of the United States or impedes the course of justice under those laws." Such a declaration, which incredibly rare, would effectively turn U.S. troops into his own police force that could be used against protestors.
The Insurrection Act has been invoked in response to 30 crises over its history, according to the Brennan Center for Justice, including by presidents Dwight D. Eisenhower and John F. Kennedy to desegregate schools after the Supreme Court's landmark ruling in Brown v. Board of Education.
The hearing was supposed to be a review of President Donald Trump's upcoming budget, which has not been released. Hegseth spoke only in broad strokes about the military's spending plan, instead highlighting recent gains in recruiting numbers and speaking in general about the importance of new technology initiatives in the Army.
On his Truth Social platform on Sunday, Trump referred to the L.A. protesters as "violent, insurrectionist mobs" and "paid insurrectionists."
The Pentagon has not had a news conference since the deployment of troops to Los Angeles, referring reporters with questions about the mission on Monday to Hegseth's posts on the social media site X.
Following his testimony, Hegseth traveled with the president to Fort Bragg in North Carolina to participate in activities tied to the Army's 250th birthday celebration.
ABC's Chris Boccia contributed to this report.