Former President Trump’s suggestion that U.S. troops could be used to go after “radical-left lunatics” following the presidential election has alarmed those in the military community and bolstered Democratic warnings about a second Trump term. Trump, who on Sunday warned he could deploy active or National Guard troops to counter the “enemy from within,” quickly drew condemnation from Vice President Harris’s campaign, which said the comments “should alarm every American who cares about their freedom and security.” Harris herself called Trump “increasingly unstable and unhinged” during her Monday campaign rally in Erie, Pa. Trump has suggested deploying the military within U.S. borders before, and his former Defense Secretary Mark Esper said the public should take Trump “seriously.” “Yes I do, of course,” Esper said Monday evening on CNN when asked whether he fears Trump would try to utilize the military against U.S. citizens. “Because I lived through that, and I saw over the summer of 2020 where President Trump and those around him wanted to use the National Guard in various capacities in cities such as Chicago and Portland and Seattle,” Esper said. Trump in an interview with Fox News that aired Sunday dismissed President Biden’s concerns that Election Day wouldn’t be peaceful and said he thinks “the bigger problem is the enemy from within, not even the people that have come in and destroyed our country.” “I think the bigger problem are the people from within. We have some very bad people. We have some sick people, radical-left lunatics,” Trump said.  “And it should be very easily handled by, if necessary, by [the] National Guard or, if really necessary, by the military, because they can’t let that happen,” he continued. The remarks quickly drew outrage from the left, with Harris’s running mate, Minnesota Gov. Tim Walz, calling Trump's comments “dangerous” and “un-American.” “As someone who wore this nation's uniform proudly ... the idea of sending U.S. military personnel against American citizens makes me sick to my stomach,” said Walz, who served for 24 years in the Army National Guard before running for public office. “It's a call for violence, plain and simple. And it's pretty damn un-American if you ask me,”  he told attendees at a campaign event in Wisconsin on Monday. The GOP presidential nominee wouldn’t immediately have command of U.S. troops should he win come November, and would only gain control following the inauguration in mid-January. Former New York Rep. Max Rose (D), a senior adviser to liberal veterans group VoteVets who serves in the Army Reserves, said what Trump and his associates are seeking to do “is not just weaponize the military but actually try to replace leaders in the military who stand up against him and follow the rule of law.” Speaking Monday evening on MSNBC’s “The 11th Hour with Stephanie Ruhle,” he added: “It just shows yet again how serious and grave these coming days are, not just this one election, but the future of this country.” And retired Army Maj. Gen. Randy Manner said he feared Trump could use the National Guard as “his own personal police force.” “If he was to be the commander in chief again, everything changes. The Supreme Court has given him immunity,” Manner said on CNN. “And the threshold for turning the National Guard into his personal police force is quite low.” Manner explained that as long as Trump had a consenting state governor, he could authorize the funds to pay them and “use the National Guard almost in any way that he wants.” “Most Americans don't know how very easy it would be for an unhinged president to use the military against our own citizens,” he added. Pushback from Republicans on Trump’s comments, meanwhile, has been virtually nonexistent. Rep. Byron Donalds (R-Fla.) appeared to be the lone Republican to publicly break from Trump on Tuesday, saying that “we’re not going to have” the U.S. military deployed inside U.S. borders.   “Obviously we don't want to have the United States military, we're not going to have that, be deployed in the United States,” Donalds said Monday on CNN. “That's been long-standing law in our country since the founding of the republic.” Donalds was among the 147 Republicans who voted against certifying the 2020 election results in January 2021. Virginia Gov. Glenn Youngkin (R) sparred with CNN’s Jake Tapper over the comments on Monday, with Youngkin refusing to accept that Trump was threatening to deploy U.S. troops against his political enemies.  This isn't the first time Trump has suggested using the military to accomplish his political goals, as he has previously opined using troops to aid in the mass deportation of undocumented immigrants. Trump also used the National Guard along with U.S. Park Police to clear Lafayette Square Park of protesters in the summer of 2020 so he could walk from the White House and pose for a photo in front of a historic church. The visit came just after Trump delivered remarks declaring himself “your president of law and order,” calling on governors to deploy National Guard units and “dominate the streets” amid sweeping racial justice protests. He also has talked of weeding out military officers who don’t share his ideology and “moving thousands of troops currently stationed overseas” to the southern border, according to his platform known as Agenda 47.  Citizens for Responsibility and Ethics in Washington (CREW), a nonprofit watchdog organization, scoured more than 13,000 of Trump’s Truth Social posts from Jan. 1, 2023, to April 1, 2024, and found that he vowed at least 19 times to weaponize law enforcement against civilians, including multiple branches of the military. While the 1878 Posse Comitatus Act largely prohibits active-duty troops from carrying out law enforcement duties inside the United States, Trump's supporters have cited the Insurrection Act of 1807 as a possible law he could use to get around that. The 200-year-old statute, which is meant to curb rebellions, was used during the Civil War and during the Civil Rights Movement. It was last used by former President George H.W. Bush during the 1992 Los Angeles riots. The law says the president, as commander in chief, can call on American troops 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.” Whether the law could be legally applied to Trump’s political goals remains to be seen. What’s far more likely are Trump’s plans to remove military officials that don’t see eye to eye with him should he return to the White House. The president is responsible for promoting officers in the military, though they would have to be approved by the Senate.