In a recent post on Truth Social, President Donald Trump said that he would invoke the Insurrection Act if local and state officials did not intervene during protests related to ICE’s immigration enforcement operations in Minneapolis. In the post, Trump characterized protesters as “professional agitators and insurrectionists” and criticized state officials for what he described as a failure to enforce the law.
Enacted in 1792 (originally as the “Calling Forth the Militia Act”), the Insurrection Act has been invoked approximately 30 times in U.S. history, including when President Dwight Eisenhower sent troops to Little Rock, Arkansas, in 1957 to enforce school desegregation and, most recently, when President George H. W. Bush responded to the 1992 Los Angeles riots.
The debate over the Insurrection Act has resurfaced, as President Trump and some members of Congress and White House advisers have expressed support for its invocation.
“The Insurrection Act is a break-glass-in-case-of-emergency kind of thing,” said Allan Stam, University Professor at UVA’s Frank Batten School of Leadership and Public Policy and a faculty senior fellow at UVA’s Miller Center. “You’re suspending democracy in a particular place for a limited but unspecified period of time.”
“The Insurrection Act is a break-glass-in-case-of-emergency kind of thing. You’re suspending democracy in a particular place for a limited but unspecified period of time.”
What is the Insurrection Act?
While often discussed in moments of crisis, the law was designed to address specific breakdowns in civil order. Enacted in the 18th century, the Insurrection Act continues to test modern democratic expectations around executive power, federalism, and civil-military boundaries.
“It was passed when a spate of separatist movements threatened to pull the new nation apart,” said UVA history professor Christa Dierksheide. “In response, congressional lawmakers granted the federal executive expansive new powers to call ‘forth the militia to execute the laws of the Union, suppress insurrections, and repel invasions.’”
As a narrow exception to the Posse Comitatus Act—which prohibits the use of federal troops for domestic law enforcement—the Insurrection Act allows the president to use the military to assist civilian authorities during crises.
“Despite the expansive powers, many understood it to be limited by custom and by the Constitution,” said Dierksheide. “President George Washington was the first to utilize the law, mobilizing state militia forces (not federal troops) to put down the Whiskey Rebellion in 1794. Five years later, President John Adams invoked the law again, this time to quell the Fries’ Rebellion.”
“President George Washington was the first to utilize the law, mobilizing state militia forces (not federal troops) to put down the Whiskey Rebellion in 1794. Five years later, President John Adams invoked the law again, this time to quell the Fries’ Rebellion.”
Still, each time it has been invoked, it has carried risks. “An army turned inward is a threat to democracy and individual liberty,” said Joseph Nunn, a counsel in the Liberty and National Security Program at the Brennan Center for Justice at NYU Law. “When the people with the guns and tanks are looking inward at a domestic political situation, there is a fundamental danger. From the founders’ perspective, this was always a concern.”
Historians note that the language was intentionally vague to empower the president to quickly deal with an emergency. “Early federal lawmakers believed this law should be used to prevent disunion, a very real threat in the 1790s,” Dierksheide said. “But the federal executive would only deploy troops if a state explicitly requested assistance to resolve a crisis.”
What was designed as a feature—granting the president flexibility during emergencies—can also look like a bug in a constitutional democracy that prizes checks and balances. And use of the act has long been debated.
Critics of the law argue that its historical origins make it ill-suited to modern governance. “This is a law designed for a 19th-century country emerging from civil war,” said Nunn. “As it stands, the Insurrection Act is archaic, overbroad, and out of date. There is a real risk of abuse, and the law urgently needs reform.”
“This is a law designed for a 19th-century country emerging from civil war. As it stands, the Insurrection Act is archaic, overbroad, and out of date. There is a real risk of abuse, and the law urgently needs reform.”
Proponents of reform are pushing for a narrower definition of when it can be invoked. “President Trump and his advisors seem to have realized that in the context of an ‘emergency,’ there is little legal precedent to bind the president, so they have enormous leeway,” said Stam. “Congress is slow by design, but it should revisit emergency powers, much like the Church Committee reviewed U.S. intelligence agencies in the 1970s. Real reform would require congressional guardrails and courts willing to enforce them. In theory, that sounds great. In practice, it’s unclear how effective it would be.”
If the Insurrection Act is invoked, what would it look like?
“For critics of the president, the use of the military domestically would simply confirm their worst fears,” said Stam. “For the president’s supporters, seeing pushback on what they believe to be reasonable policies leaves them increasingly alienated from the other side of the partisan divide.”
That polarization underscores a fundamental question of when to exert federal power. “Any time the government resorts to force instead of law and courts, it reflects a failure somewhere in the system,” said Nunn. “The more frequently the government relies on force, the more it undermines the idea that we live in a rules-based democratic system rather than one governed by coercion.”
“Any time the government resorts to force instead of law and courts, it reflects a failure somewhere in the system. The more frequently the government relies on force, the more it undermines the idea that we live in a rules-based democratic system rather than one governed by coercion.”
Even when leaders decide force is justified, how that force is applied can matter too. “In the military, job one is to protect the people you’re working with, and job two is the mission,” said Stam. “That increases the risk of accidentally harming noncombatants, because self-protection dominates decision-making. Policing is fundamentally different. ‘To serve and protect’ means the citizen comes first, the officer second. The problem arises when military-trained individuals move into policing. What we could see is a mismatch of training and instincts.”
Technology can complicate matters further. A deployment now would unfold in real time on social media, shaping public perception immediately. Stam likens the ubiquity of video to instant replay during a football game, which oftentimes intensifies disagreement about what actually happened, depending on prior allegiances.
Ultimately, the Insurrection Act embodies a tension the Constitution never fully resolves: how a democracy defends itself without undermining its own principles. Legal authority and democratic legitimacy are not always the same. A president may have the legal power to invoke the Insurrection Act, but the exercise of that power still raises questions about proportionality, necessity, and public consent—questions that law alone cannot settle.
When presidents talk about invoking it, the issue is not merely whether they can, but whether they should, and under what constraints.