What Trump can and can’t do with the Insurrection Act

Demystifying the most ominous law in America

Pablo Martinez Monsivais/Associated Press

In the United States, the military is not used for domestic law enforcement. That’s a bedrock civic principle, one that separates our democracy from dictatorships around the world. Our troops serve to protect the American people from harm coming from abroad, not to police people at home.

Legally speaking, though, there is one glaring exception: The Insurrection Act.

Enacted at the turn of the 19th century, the law allows a president to deploy the U.S. military domestically for “any insurrection, domestic violence, unlawful combination, or conspiracy,” and permits those federal troops to directly perform civilian law enforcement actions like making arrests, detaining citizens, and enforcing court orders — normally barred under the Posse Comitatus Act. Unrest so severe it could topple the republic was hardly a fantasy at the time: The French Revolution was a fresh memory, as was the Whiskey Rebellion, and another war with the British was on the horizon.

This year’s National Guard and Marines deployments have been a mix of state deployments and federal missions under President Trump’s control. Because Trump has not invoked the Insurrection Act, the federal troops he has directed to Chicago, Los Angeles, and Portland have been subject to the Posse Comitatus Act and its strict limitations about how they can operate within the U.S. If the president invokes the Insurrection Act, however, troops under his command would be allowed to function as an extension of state or federal law enforcement.

Think of it this way: The Posse Comitatus Act prohibits the federal government from using the military to enforce the law domestically except when the president invokes the Insurrection Act. The Insurrection Act has rarely been used, and only then in moments of real crisis. Lincoln used it to send troops into seceding states; Grant to put down Ku Klux Klan violence. Eisenhower and Kennedy invoked it to enforce desegregation in the South.

Today’s challenging political circumstances do not represent such a crisis.

Trump is creating fake emergencies as a pretext for his unconstitutional power grabs on a number of fronts. He has, incorrectly, claimed that the trade deficit constitutes an economic crisis that necessitates the novel use of emergency powers to implement a sweeping tariff regime, representing one of the largest tax hikes in our nation’s history. He has, wrongly, declared the country is being “invaded” by immigrants to activate war powers to detain people and send them to foreign prisons without due process. More recently, he issued an executive order to tag members of his political opposition as “terrorists” without merit. And now he is frequently toying with the notion of invoking Insurrection Act powers without any concrete purpose at all, save, perhaps, to continue and expand the deployment of National Guard and other military personnel in communities around the country — under the vague pretext of combating crime and facilitating DHS immigration operations.

Read more: Eight things to know about the National Guard in Washington D.C.

While invocation would represent an egregious abuse of the military and executive powers, it is important to remember our democracy can nonetheless withstand such an event. Despite what Trump says, the Insurrection Act does not give the administration unconstrained, dictatorial powers.

Here’s what the Insurrection Act does and doesn’t do.

What the Insurrection Act allows: Military engagement in civilian law enforcement on U.S. soil

Invocation of the Insurrection Act allows the president to deploy troops to directly and openly participate in law enforcement — an escalation from the more limited, supportive role that the troops currently deployed around the country are performing. However, this authority is conditioned on the existence of extraordinary circumstances (i.e., an actual “insurrection”) that prevent local and state authorities from executing the law and protecting constitutional rights.

In other words, Trump invoking the Insurrection Act could very well be illegal and struck down by the courts.¹

Setting aside the ultimate questions of legality, though, invocation of the Insurrection Act would likely carry at least some of the following consequences:

• More active-duty troops pulled away from critical national security roles around the world. Instead, they could be redeployed to serve as a political show of force on American streets.

• Expanded attempts to use soldiers and military infrastructure and equipment for direct law enforcement roles — like making arrests or policing protests.

• Higher risk of violent incidents. Without the rigorous and ongoing training, there is an increased likelihood of tragic accidents and violence. Earlier this year, a Mine-Resistant Ambush Protected All-Terrain Vehicle collided with a “civilian vehicle” on Capitol Hill in Washington, D.C.

• Danger of unlawful intimidation and violations of constitutional rights. Armed soldiers patrolling the streets and confronting protesters would discourage dissent and chill free speech for all of us. The intimidation is the whole point. (Whether or not they would succeed is a different question.)

• Decreased trust in the institution of the military. Already, Donald Trump’s political machinations have shaken the country’s faith in an institution that has historically commanded wide respect. This would make that problem much, much worse.

• Loss of morale and unit cohesion across the armed forces. American soldiers understand the political agenda being pushed by the White House in trying to deploy soldiers domestically. Demoralization over being used as a political prop will likely ripple through the armed forces, as well as harm future recruiting and retention.

What the Insurrection Act does not allow: License to break the law or violate the Constitution

The Insurrection Act is not a carte blanche to deploy troops against U.S. citizens.

It cannot be lawfully invoked to respond to Americans peacefully exercising their constitutional rights. Nor does it impose martial law, disrupt the role of courts to administer the law, suspend civil liberties, or give the president the authority to interfere in elections. If it did any of those things, it would amount to a self-destruct button on the Constitution. It is not that.

Instead, soldiers deployed domestically under the Insurrection Act — including if redirected to law enforcement roles — would still be required to follow the law and relevant regulations on the use of force. Military personnel swear an oath to uphold the Constitution. And the past few months have put on clear display how seriously our service members take this duty: Public reporting has uncovered a tiny number of incidents of alleged misconduct amidst thousands of deployed National Guard troops, despite deliberate efforts by the administration to stoke tensions in the affected communities. Contrast this with DHS personnel — ICE and CBP, in particular — whose reported allegations of illegal detentions and excessive force grow by the day.

There are also several key constraints that federal courts have already imposed (or would be likely to impose) on the administration:

• First, courts might block an unlawful invocation. As noted above, even a deferential judiciary could enjoin the president’s abuse of these authorities if the pretext and bad faith are obvious enough. (For more on the possible legal issues, see our paper on the topic: Legal Challenges to an Invocation of the Insurrection Act.)

• Second, even if an invocation stands, expect courts to continue to closely scrutinize the behavior of troops once deployed. Right now, courts across the country are carefully evaluating both National Guard deployments and the activities of federal law enforcement agencies. This sort of litigation — including our lawsuit on behalf of protesters and the press in Chicago — would continue even if the president attempts to throw the Insurrection Act into the fray.

• Finally, any unconstitutional behavior or violation of individual rights will still be illegal. Military personnel do not have special powers to violate rights and must follow the same domestic laws and rules as ICE, CBP, or local law enforcement, as well as adhere to military law. Soldiers and commanders alike can potentially face consequences for breaking the law.

Deployments are unpopular — and generate opposition

When Trump considered invoking the Insurrection Act in 2020 during the height of the Black Lives Matter protests, many high-ranking members of America’s military leadership spoke out against such measures, including senior leaders who served under Trump like Gen. (ret.) James Mattis, the former defense secretary, and Gen. (ret.) John Kelly, the former White House chief of staff.

Similarly, Senate Republicans and governors, such as Oklahoma’s Gov. Kevin Stitt and Vermont’s Gov. Phil Scott, have already criticized Trump’s deployment of troops onto American streets to fight crime or support law enforcement.

More generally, domestic military deployments are already extremely unpopular.

And that’s not just among voters in blue states and cities.

A Gallup poll in early October found that roughly six in 10 Americans oppose the use of the military or National Guard to combat crime in cities.

We also conducted our own poll in October to gauge public opinion in communities not (yet) directly affected by National Guard deployments. In a survey of 600 likely voters in Iowa, here’s what we found:

• 63 percent of Iowans believe the recent military and National Guard deployments are dividing Americans.

• 69 percent of Iowa voters believe it would be better to increase funding for local law enforcement rather than spending huge sums of taxpayer money on military deployments.

• 63 percent of voters surveyed said that governors are in command of states’ National Guards and a president deploying them over a governor’s wishes undermines states’ rights and the Constitution’s separation of powers.

• 50 percent of Iowans believe that President Trump’s deployment of military and National Guard to Democratic-run cities is a political stunt.

• Over 20 percent of Iowa Republicans oppose the latest federal deployments of the National Guard.

See full poll results here.

Now imagine Trump using the Insurrection Act to put soldiers on the streets of Des Moines or Dubuque? The administration’s actions are already unpopular even though neither local Guardsmen nor civilians have had to deal with the hassles and dangers of the recent deployments.

To be sure, invocation of the Insurrection Act would represent a dramatic intensification of an already troubling set of circumstances. The law is vague and too broadly written — and in great need of reform — but it is not a free pass for President Trump or members of the military to violate our constitutional rights.

1. Previous presidents have respected the grave nature of these powers, so rarely was there any doubt that the statutory requirements were met when the Insurrection Act was invoked in the past. Yet the presumption of good faith afforded to other presidents does not apply to the current occupant of the White House after five months of pretextual and overtly political domestic deployments.

It is an open question how the courts would handle the legal challenges should the president go down this path. While there is consensus that the law gives the president at least some discretion, allowing him to declare there’s an “insurrection” whenever he feels like it would defeat the point of the Insurrection Act being an exception to the Posse Comitatus Act. While this Supreme Court has welcomed opportunities to expand other aspects of executive authority, the stark prospect of troops arresting people on the street around the country might be a step too far.