President-elect Trump has talked about using the military on the “enemy from within,” at the border and potentially even in Mexico against cartels.
The rhetoric has sparked increasing worry among Democrats on Capitol Hill as Trump heads toward his second term. Republicans, however, largely downplayed the concerns during interviews this week.
Rep. Adam Smith (D-Wash.), ranking member of the House Armed Services Committee, said he was concerned about troops being deployed in the U.S., particularly after the selection of Pete Hegseth, a Fox News personality and veteran with far-right views, as the new Defense secretary.
“A lot of people who have worked in the Pentagon or worked in the military have, over the course of their career, clearly expressed their firm commitment to the fact that domestic law enforcement isn't something the military should be doing,” he said. “It is one of many concerns.”
But Rep. Doug Lamborn (R-Colo.), also an Armed Services Committee member, deflected the concerns, like several Republicans approached by The Hill.
“I think a lot of these ideas are not very far advanced to be able to discuss with a lot of specificity,” he said.
During the campaign, Trump explicitly floated using the military on protesters or against enemies in the “radical left,” to assist with mass deportations of illegal immigrants and wage a war against cartels in Mexico.
Trump’s first term in office saw him stymied at times by senior military and Defense Department officials, but in a second stint in office, his opponents fear Trump will install absolute loyalists willing to act on his impulses.
Notably, Trump was stopped from potentially misusing the military in 2020 by former Secretary of Defense Mark Esper, who Trump fired in November of that year. Esper broke with Trump over invoking the Insurrection Act to deploy active-duty troops against protesters in the wake of the death of Georgy Floyd.
In a second term, critics worry Trump will also have much more leeway after the Supreme Court this year ruled the president cannot be criminally prosecuted for official acts. Official acts would include military orders, but service members follow the Uniformed Code of Military Justice (UCMJ) and have to still obey laws regardless of the commander in chief's directions.
Trump, in an October interview on Fox News, spurred concerns across Washington when he said “the bigger problem is the enemy from within,” rather than external threats, leading up to Election Day.
“We have some very bad people. We have some sick people, radical-left lunatics,” the president-elect said. “It should be very easily handled by, if necessary, by National Guard, or if really necessary, by the military, because they can’t let that happen.”
Esper said last month that Americans should take Trump’s threats to use the military “seriously.”
On Capitol Hill, Democrats sounded a similar warning.
Rep. John Garamendi (D-Calif.), who sits on the Armed Services Committee, said Trump has pledged to “use the military to straighten out America, to make America great again.”
“So why would we not take him at his word?” he said. “We should be concerned.”
Garamendi warned that a sitting president has “extraordinary power” to deploy the military.
The Insurrection Act of 1807 grants the president broad powers to deploy the military to quell unrest so long as it greatly hinders the functions of the state. It is partly limited by the Posse Comitatus Act of 1878, which says the military cannot be used to enforce domestic laws and assist law enforcement unless specifically authorized by Congress.
Rep. Sara Jacobs (D-Calif.), also on the Armed Services Committee, said Posse Comitatus is a “fundamental principle of our armed forces, and it is illegal under the UCMJ to follow an illegal order.”
“I represent the biggest military community in the country so I know that our service members should only be deployed as a last resort — and never against the American people to stifle dissent,” she added in a statement.
But Rep. Mark Alford (R-Mo.), another Armed Services Committee member, brushed off the concerns. “Trump is not going to [target] U.S. citizens inside the United States of America or anywhere else for that matter,” he said.
Trump has also pledged to deploy the military to the border, a move that many in the GOP are now embracing.
Although National Guard troops have been moved to the border before, the scope envisioned by Trump and Republicans would be unprecedented.
The 2024 Republican platform calls to “use any and all resources needed to stop the invasion of our country, including moving thousands of troops currently stationed overseas in countries that don't like us.”
The GOP document also says it will “deploy the U.S. Navy to impose a full fentanyl blockade on the waters of our region — boarding and inspecting ships to look for fentanyl and fentanyl precursors.”
“Project 2025,” a blueprint from the conservative Heritage Foundation for the Trump administration, outlines clear plans for military use at the border. Trump has distanced himself from parts of the document.
Gene Hamilton, former counselor to the attorney general in the Trump administration, wrote Project 2025’s Department of Justice chapter that calls for “active-duty military personnel and National Guardsmen to assist in arrest operations along the border.”
Democrats raised fearful questions about what such a deployment would mean.
“Using the military for domestic purposes, which is inappropriate, totally inappropriate,” said Garamendi, “sets America on a [dangerous] course.”
Republicans have also been warming to the idea of deploying the military into Mexico as part of the broader fight against drug trafficking and illegal immigration.
In the Republican primaries, several candidates, including second-place finisher Nikki Haley and Florida Gov. Ron DeSantis, recommended taking some kind of military action against the cartels in Mexico.
Trump has not made explicit mention of action against cartels, but his close allies, including his former deputy secretary of Homeland Security, Ken Cuccinelli, have publicly advocated for it. Cuccinelli wrote the Homeland Security chapter in Project 2025.
Trump’s pick for national security adviser, Rep. Mike Waltz (R-Fla.), previously introduced legislation to authorize the use of military force against cartels.
And Trump's incoming border czar, Tom Homan, told Fox News this week that he will “absolutely need military and special ops” to take on cartels.
The Hill previously reported how military action in Mexico would threaten to upend relations with Washington’s biggest trading partner and would not likely solve the underlying problems that have led to the cartel’s vast power.
In his first term, Trump considered dropping bombs on drug labs in Mexico, according to Esper.
Sen. Marco Rubio (R-Fla.), Trump’s pick for secretary of State, has supported sending troops to Mexico “as long as there is cooperation from the Mexican government.”
“I would be willing to support this measure, but it has to be in coordination with the armed forces and the Mexican police force. Otherwise, it would not be possible to do it,” he told El Universal in 2023.
But Democratic lawmakers are worried that Trump, who has already threatened massive tariffs on Mexico, will make a unilateral move and further degrade relations with America’s neighbor.
Jacobs raised concern about an “unjustified and unauthorized invasion of our biggest trading partner,” saying it would “likely cause the cartels to retaliate and ironically increase refugees coming to the United States to escape the violence that we caused.”
“Someone who lives in Mar-a-Lago couldn’t possibly understand the consequences of deploying our troops to the border and into Mexico with whom we work daily on issues from commerce to tourism to counterterrorism and cross-border pollution,” she said.
“Going to war in Mexico,” added Armed Services Committee ranking member Smith, “I don't think would be a good idea.”
