Posse Comitatus and the Insurrection Act

The limitations on Trump deploying the military in terrifying ways are almost non-existent.

Photo: Doug Mills/The New York Times

A major difference between our democracy and autocracies around the world is that our military is not something that the president can use against his internal enemies. Our military is traditionally non-political, and that has kept us from being ruled by a junta or a strongman because such a dictatorship would need the military’s cooperation to impose and keep martial law in place.

That has been the line left largely uncrossed since 1878, when the Posse Comitatus Act was first passed. That phrase refers to a group of locals mobilized by the sheriff to suppress lawlessness in a county. The Posse Comitatus Act prevents troops from being used this way on orders of the President.

Today, we’ve reached a dangerous inflection point, where that safeguard could be easily circumvented by Donald Trump should he be reelected. He has long promised to go after his political rivals, whom he now openly labels “enemies from within.” And he has made recent suggestions that he could use the military or the National Guard to suppress dissent.

But it goes even further than political retribution. Trump and his cronies have plans for the military that, once implemented, would render America wholly unrecognizable as a liberal democracy.

Today, I’ll discuss the origins of Posse Comitatus Act and how Trump might get around it using something called the Insurrection Act. Then I’ll note a few key ways Trump has threatened to use the military under the Insurrection Act if he becomes Commander-in-Chief again. This next time around, heaven forbid it should really happen, there won’t be any institutional guardrails or cooler heads in the room to keep him from doing so.

A dark origin to an important limitation

When we consider the principle that federal troops should not be used to enforce the will of the White House upon its political opponents, it seems a noble and good idea. But at the time this law was enacted, like so many other parts of our history, the record contains some hard and bitter truths.

Prior to the statute’s enactment in 1878, federal troops were used in many ways we would find repellant today. These included persecuting indigenous populations along the frontier and capturing and returning fugitive slaves.

President Rutherford B. Hayes signed the bill into law following the contentious and disputed election of 1876, when Hayes became president through a brokered deal that saw the withdrawal of federal troops from the South, thereby ending Reconstruction. Those troops, however, were the only thing keeping the Southern states from suppressing their Black citizens, who had recently been freed from slavery following the Civil War. 

Without federal troops in the South, the white majority quickly disenfranchised Black voters and instituted a racial caste system under Jim Crow. Millions of Black lives were suddenly without federal protection, and terrifying local mobs and lynchings became commonplace in order to enforce white supremacy and white rule.

Also during Hayes’s term, labor unrest grew around the country as economic conditions deteriorated. The Great Railroad Strike of 1877 began after local militias fired upon striking workers, and as tensions mounted, the National Guard, supported by federal troops, was called in to suppress the striking workers. Over 100 people were killed in the ensuing violence.

The passage of the Posse Comitatus Act the following year prevented federal forces from being used to put down such labor unrest. The Act, as amended since, is just one sentence long, but it has become a linchpin of our democracy:

Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army, the Navy, the Marine Corps, the Air Force, or the Space Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.

Note that the Act does not apply to the National Guard when activated by a state’s governor in response to emergencies such as rioting or natural disasters, as we’ve recently seen in the South.

Today, the Act stands for the principle that the military cannot interfere in civilian affairs absent express legal authority. And that’s where Trump has sought to blast a hole.

Trump’s love for the Insurrection Act

Trump is a big fan of the Insurrection Act, which is something of an amalgam of acts passed between 1792 and 1871. I’ll get to what the Insurrection Act actually says a bit later, but first I want to discuss how enamored Trump was of the statute during his first term.

During the Black Lives Matter protests in the summer of 2020, Trump frequently raised the notion of invoking the Insurrection Act to quell unrest triggered by the killings of George Floyd and other Black citizens by the police. The last time it had been invoked was in 1992. President Bush had invoked it to quell violent riots in Los Angeles following the jury acquittal of police assailants of Black motorist Rodney King.

But Trump’s own generals and advisors balked at the idea of Trump invoking it in 2020, worried that he would use it as a pretense to stoke further violence or even impose martial law. They worked furiously behind the scenes to keep him from being able to deploy troops.

Indeed, his own Defense Secretary, Mark Esper, was so concerned about what Trump would do with active duty federal troops from the 82nd Airborne Division, which had been stationed near D.C., that he had them sent home to their base in North Carolina “as quickly as possible.”

As the Post reported, Esper wrote about this in his book covering his time in office:

At this point, even if we were wrong and violence spiked in the city, I didn’t want active-duty forces quickly available to the president. We had managed to keep them out of the District so far. Guard forces were now flowing into D.C. in healthy numbers, so I decided to send all active-duty units home. I didn’t inform the White House about these decisions either. I couldn’t trust they wouldn’t reverse my decision.

I had to read that last part again. Esper, the Defense Secretary, didn’t inform Trump, the Commander-in-Chief, about what he had done. He was afraid his decision would be overturned so he sent them back to base in secret.

Esper had also told reporters publicly that he did not support using the Insurrection Act to quell the unrest. Esper wrote that Trump “launched into a tirade” against him and accused him of betrayal.

On December 18, 2020, while Trump was conspiring with advisors to overturn the results of the 2020 election, some of them from “Team Crazy,” which included Ret. Gen. Michael Flynn, supported him issuing an order invoking the Insurrection Act so that the military could seize voting machines. The idea that Trump could call in federal troops and take over local elections in any way, especially in the absence of any actual insurrection, was shocking. Although an order was drafted up, Trump never invoked the Act.

Trump has far fewer compunctions today. As the Washington Post reported this Friday morning,

Trump has named his unfulfilled demands to deploy the military against civil unrest as one of his top regrets—and one he aims not to repeat. His allies have laid plans for him to do so by invoking emergency authority under the Insurrection Act of 1807.

Specifically, the Post ran a story nearly a year ago about how Trump’s now indicted co-defendant Jeffrey Clark, formerly of the Justice Department, was heading up plans at Project 2025 for how to use the Insurrection Act under a Trump presidency. Clark is in fact a big fan of its use: During the 2020 election, he suggested it could be used to put down civil protests should Trump overturn the election. According to Jack Smith’s original indictment, a deputy White House counsel warned Clark that a refusal by Trump to leave office would lead to “riots in every major city.” Clark responded, “That’s why there’s an Insurrection Act.”

Invoking the Insurrection Act is too easy

Given Trump’s stated intention to invoke the Insurrection Act, it’s worth reviewing what it actually says and permits. Under that law, the president can create an exception to the Posse Comitatus Act and call in U.S. armed forces and the National Guard under three circumstances:

• when requested by a state to address an insurrection against that state;

• to address an insurrection, in any state, which makes it impracticable to enforce the law;

• to address an insurrection, domestic violence, unlawful combination or conspiracy, in any state, which results in the deprivation of a constitutionally secured right, and where the state is unable, fails or refuses to protect those rights.

As an initial problem, the Insurrection Act doesn’t define what an insurrection is. When the statute has been interpreted by the courts, they have tended to expand presidential powers and allowed the White House to decide whether conditions to deploy the military have been met. Trump getting to decide when Trump gets to use the military is a frightening thought.

Also, go back now and read that last bullet point once more. You’ll quickly understand that there doesn’t have to be any actual “insurrection” or even violence in a state for the president to invoke the Act. In theory, there just has to be a “conspiracy” that threatens a constitutional right, where the state has refused to take action.

You can see how this could get twisted quickly in the wrong hands. As president, Trump could falsely claim, as he already has as a candidate, that migrants are making a certain blue city unsafe, but that “radical leftists” in the state government are allowing it to happen as part of a conspiracy to create more Democratic voters. Under the guise of protecting ordinary citizens from such dangerous enemies, Trump could send in federal troops to blue cities.

Believe Trump’s threats

The idea that federal troops would be sent into cities to quell “crime” during a second Trump term is something he has said openly that he will do. As the New York Times reported in August, he has been making this threat for over two years now:

“In places where there is a true breakdown of the rule of law, such as the most dangerous neighborhoods in Chicago, the next president should use every power at his disposal to restore order—and, if necessary, that includes sending in the National Guard or the troops,” Mr. Trump said at a conservative conference in Dallas in August 2022, shortly before announcing that he was running to be that next president.

Trump has also said he’ll be a “Day One” dictator, meaning he could invoke the Insurrection Act on his very first day in office. If that sounds insane, imagine this not so far-out scenario: Trump begins to gin up rumors of violent protests around his inauguration, so he drafts a standing order to invoke the Insurrection Act on Day One to address “civilian unrest” and then signs it as soon as he gets to the Oval Office. The military clashes with protestors, and some citizens are killed. The “violence” then justifies even greater troop presence.

Rather distressingly, there’s nothing in the law that can stop Trump from doing that, once again because the drafters of the Insurrection Act over the many decades probably could never have imagined it being abused in this way.

But Trump won’t stop there. He wants to deploy U.S. troops, if needed, to round up undocumented immigrants and lock them inside militarized camps. He says he will begin with “the criminals,” but how will federal troops determine who these people are? Is anyone who looks like they might be an immigrant and who travels inside the United States without “papers” suddenly suspect?

And as many historians of fascism note, when prison camps are built to house the “enemies” of the state, they are often used shortly afterwards to house many others. The death camps in Germany, for example, were built first as way to hold and punish political dissidents who opposed the Nazi regime.

Trump also wants to militarize our southern border, turning our country into “Fortress America” where the army might easily shoot first and asks questions later. The whole point of dehumanizing migrants as “animals” is to permit atrocities to occur against them. And if we position troops at our border the way Trump wants to, it won’t be long before those same troops begin policing inward, looking for undocumented migrants among our border towns and cities.

We must prepare, even as we fight to keep him from office

I understand that the enumeration of these plans does little to alleviate the anxiety we all feel in these final days of the election. But we cannot defeat MAGA fascism unless we are clear-eyed about the dangers it poses to our democracy. 

That means confronting these horrors directly, condemning them roundly, and convincing enough voters of good mind and conscience that we simply cannot go down this path. Remaining steadfast and informed through this nightmarish storm also allows us to prepare to resist Trump at every step should he—heaven forbid—win reelection. 

I do not believe he will prevail, but we should not and cannot ever simply assume he will fail. And should we win a trifecta in government, in this or any future government, we must immediately reform the Insurrection Act to prevent future fascists from abusing it to seize and hold power.

This must become a top priority.