Understanding the Insurrection Act: Presidential Power to Deploy Military Forces on US Soil

The legislation allows military forces to participate in domestic law enforcement operations.

US President Donald Trump declared on Monday that he might invoke the Insurrection Act, a law that authorizes the president to deploy military forces within the United States, if courts and governors continue to obstruct his deployment of National Guard troops in Democrat-led cities.

Here's an explanation of this centuries-old legislation.

WHAT IS THE INSURRECTION ACT? The Insurrection Act is federal legislation that grants the US president authority to deploy military forces or federalize National Guard troops within the United States to suppress domestic uprisings.

The law is commonly known as the Insurrection Act of 1807 because President Thomas Jefferson signed it into law that year. However, the modern Insurrection Act actually combines various statutes passed between 1792 and 1871 that define the role of US military forces in domestic law enforcement.

This legislation enables troops to engage in domestic law enforcement activities such as making arrests and conducting searches, functions they are generally prohibited from performing otherwise.

The Insurrection Act can be activated when there are "unlawful obstructions, combinations or assemblages or rebellion" against the US government's authority. Once the president determines these conditions exist, the law empowers the president to use armed forces to "enforce those laws or suppress the rebellion."

When Trump deployed the National Guard to Los Angeles and other cities this summer, he relied on a different legal provision, Section 12406 of Title 10 of the US Code, which permits the president to bring the guard into federal service.

Unlike the Insurrection Act, Section 12406 forbids the National Guard from executing civilian law enforcement activities. This means they can protect federal officers and property but cannot make arrests.

WHY IS THE INSURRECTION ACT SO CONTROVERSIAL? There is a long-standing American tradition of keeping federal military forces separate from civilian affairs.

The nation's founders, having experienced abuses by British military forces during colonial times, worried that giving the president unlimited control over troops would undermine civil liberties and democratic processes, according to constitutional scholars. Under the US Constitution, governors typically have authority to maintain order within state boundaries.

These principles are codified in the Posse Comitatus Act of 1878, which generally prohibits the military from participating in civilian law enforcement. The Insurrection Act functions as a statutory exception to the Posse Comitatus Act.

Civil rights organizations have long cautioned that the Insurrection Act gives the president extensive authority to use the military as a domestic police force in ways the founding fathers never intended.

WHAT HAS TRUMP SAID ABOUT THE INSURRECTION ACT? Trump informed reporters in the Oval Office on Monday that invoking the Insurrection Act has not been necessary thus far, but he would consider doing so.

"We have an Insurrection Act for a reason," Trump stated. "If people were being killed and courts were holding us up, or governors or mayors were holding us up, sure, I'd do that."

During his first presidential term, Trump suggested he would utilize the Insurrection Act to quell unrest following George Floyd's death, an unarmed Black man killed in police custody, but ultimately did not invoke it.

HAS THE INSURRECTION ACT BEEN USED BEFORE? Yes. The Insurrection Act has been invoked dozens of times throughout American history. Since the civil rights movement of the 1960s, however, its use has become "exceedingly rare," according to a Congressional Research Service report.

The Insurrection Act was last implemented in 1992, when the acquittal of four Los Angeles police officers in the beating of Black motorist Rodney King triggered deadly riots. California's governor had requested military assistance from President George H.W. Bush to control the violence.

CAN TRUMP SEND IN TROOPS WITHOUT A GOVERNOR'S APPROVAL? Yes. The law outlines scenarios where presidential approval from a state's governor or legislature is required, and instances where such approval is unnecessary.

Historically, when the Insurrection Act was invoked, presidents and governors have typically agreed on the need for military intervention.

In 2005, former President George W. Bush decided against invoking the Insurrection Act to deploy active-duty troops to Louisiana following Hurricane Katrina, partly because the state's governor opposed the action.

CAN A COURT STRIKE DOWN TRUMP'S APPLICATION OF THE LAW? Courts have historically been very reluctant to question a president's military declarations, and the 9th US Circuit Court of Appeals recently stated that the president's decision to deploy the military deserves a "great level of deference."

However, some legal experts argue that this deference does not completely prevent courts from reviewing presidential decisions. An Oregon federal judge recently ruled against Trump's decision to send troops to Portland protests by invoking Section 12406, writing that "'a great level of deference' is not equivalent to ignoring the facts on the ground."