This blog was written by LWV's Summer 2025 legal interns.

How far can a president go in using military force on US soil? 

In moments of political uncertainty, concepts like the Insurrection Act or “martial law” can feel abstract — until they don’t. Given the current administration’s recent federal deployment of the National Guard in California and federal takeover of Washington, DC, many are wondering: what is martial law? Does the president have the right to use military force in our cities? Are we on the brink of something more dangerous?  

The League of Women Voters is committed to the belief that democracy depends on an engaged and educated public, especially when civil liberties are at stake. We the people deserve answers, critical context, and a clear-eyed perspective on what this moment means for our democracy. History has shown that when communities understand their rights, they can shape the future, even in the face of federal overreach. 

While this blog focuses on the use of the National Guard in Los Angeles, a future blog will examine the 2025 federal takeover of Washington, DC. 

What is the National Guard? 

The National Guard is a reserve force of the military and consists of 54 organizations (one for each US state, DC, and three US territories). Individuals in the National Guard typically serve part-time under the US Air Force or Army. They attend regular training and may be called into action in an emergency, such as a hurricane, earthquake, or invasion. 

When the National Guard is called to service, members can serve under three different statuses: State Active Duty (SAD), Title 32, or Title 10.  

1. SAD status is invoked under state authority for assistance with a state mission and can only be ordered by a governor. For example, a governor can deploy the National Guard to help with a natural disaster confined to their state.
2. Missions under Title 32 status may include responding to natural disasters affecting multiple states or increasing border security. Under Title 32 status, the National Guard can be activated by a governor; however, under the National Defense Authorization Act for fiscal year 2007, the President can also use Title 32 to call up the National Guard. The Guard personnel continue to operate under state command no matter who calls upon them. Commentators have noted that although the precise contours of Title 32 authority are unclear, given that both the president and state governors can utilize it, there are some limitations to the president’s power in these instances. These include permitting governors to decide whether to participate and following the constitutional principles of state sovereignty.
3. Under Title 10 of the US Code, only the President can call the National Guard to act under federal authority for a federal mission, such as US military action in a foreign nation. 

The distinctions between the statuses matter because they determine the activity that the National Guard can lawfully conduct. For example, under Title 10 authority, the Posse Comitatus Act of 1878 limits the activities that the National Guard can conduct when called by the president, absent other explicit statutory authorization. Additionally, constitutional principles like state sovereignty govern the president's ability to send military personnel into states and limit the National Guard's actions when called by the president rather than a state governor. 

Sending the National Guard to Los Angeles 

In early June 2025, President Trump sent the California National Guard into Los Angeles to support Immigration and Customs Enforcement (ICE) agents and protect federal property amidst peaceful protests.

President Trump issued a memorandum claiming there had been “[n]umerous incidents of violence and disorder.” It’s important to note that, though there were limited instances of violence, the demonstrations against federal immigration raids were largely peaceful. Some videos shared as proof of the “violence and disorder” were instead from 2020 protests and an intense soccer match. By mid-July, the LA Times was able to report that the still-deployed Marines and National Guard troops were not fighting “violent, insurrectionist mobs,” but “tedium.”    

President Trump stated that Los Angeles protests against the unlawful detention and removal of immigrants “constitute a form of rebellion against the authority of the Government of the United States.” In the memo, he asserted authority under 10 USC § 12406 to call the 2,000 members of the California National Guard into federal service for 60 days “to temporarily protect...United States Government personnel who are performing Federal functions, including the enforcement of Federal law, and to protect Federal property.” On June 9, President Trump ordered an additional 2,000 National Guard members and 700 United States Marines to be deployed to Los Angeles.   

After President Trump deployed the Marines, California Governor Gavin Newsom and Attorney General Rob Bonta filed a challenge to the order. The challenge stated that President Trump had unlawfully federalized the California National Guard by not obtaining Governor Newsom’s consent. Although the district court judge ruled that President Trump’s order was unlawful on June 12, 2025, the US Court of Appeals for the Ninth Circuit then ruled that isolated acts of violence within LA sufficiently interfered with ICE activities to “likely” warrant the action. This allowed the Guard’s deployment to remain in effect on June 19, 2025. The Ninth Circuit also affirmed long-standing restrictions on the activities in which the National Guard may engage during the deployment and rejected the Justice Department’s claim that presidential emergency declarations cannot be reviewed by the courts or state governors. 

Lawyers from the California Attorney General’s office and the Justice Department were back before the district court on June 23, 2025, for arguments on other issues raised in the suit, including whether the deployment was still necessary. AG Bonta’s team requested additional information on National Guard deployments to areas more than 100 miles away from Los Angeles. On June 24, the district court ordered an expedited, limited discovery, directing the Trump Administration to produce documents, photos, internal reports, and other evidence detailing the military’s activities in Southern California. A preliminary injunction hearing was scheduled for August 11, 2025.

Further updates on the case progression can be found here. 

Were President Trump’s Actions in LA Legal? 

President Trump called the National Guard into California under Title 10 authority only. Under Title 10 status, the National Guard is subject to the Posse Comitatus Act and referred to as “federalized,” because it functions under presidential (federal) command. While there are some exceptions to this prohibition, they only apply if the president takes additional steps like invoking the Insurrection Act.  

Invoking Title 10 on its own prohibits the National Guard from carrying out civilian law enforcement activities due to Posse Comitatus. President Trump’s order did not detail specific activities troops may engage in, raising questions about the legality of troops accompanying ICE agents on raids and detaining individuals. 

The Tenth Amendment and the Anti-Commandeering doctrine limit the extent to which federal officers can intervene in state affairs. However, once Title 10 authority is invoked, the National Guard forces become federalized, negating anti-commandeering principles. While the language of Title 10 provides that orders “shall be issued through the governors of the States,” the President has been permitted to activate a state’s National Guard absent a request from the state’s governor under rare circumstances. While the complaint by California challenging President Trump’s actions asserts that the statutory text prohibits such deployments, commentators have described §12406 of Title 10 as “‘troublingly ambiguous,’” and indicated that this complaint places this question “squarely before the courts.” The Ninth Circuit ruling exploited this ambiguity by relying on the judicial principle of deference to the president in matters of national security.

Has This Happened Before?

The last time a President called in the National Guard under Title 10 without consent of the governor occurred in 1965 when then-President Lyndon B. Johnson ordered the Guard to protect civil rights protestors in Selma, Alabama. President Johnson’s use of the National Guard was based on evidence that protestors were being violently assaulted and that Alabama's governor failed to effectively address the violence. Unlike the events in Selma, events in California this month were largely non-violent. A professor at McGill University called the situation under the Johnson administration “a reactionary segregationist counterinsurgency” and the situation in Los Angeles “a manufactured conflict.” 

Additionally, a similar though not identical situation occurred in 2020 when President Trump utilized Title 10 to call in members of the National Guard to Washington, DC, amidst protests following the police murder of George Floyd. The current situation in California with ICE protests differs because, unlike DC, California is a sovereign state. The President invoked his Title 10 authority to activate the California National Guard without Governor Newsom’s consent. 

Although California’s state National Guard is being utilized, they are not under state command. Due to Trump’s exercise of Title 10 authority, they are considered federalized troops under presidential command. As a result, the situation invokes state sovereignty concerns that were not involved in DC in 2020.  

As stated earlier, a future blog will go into greater detail about the 2025 federal takeover of Washington, DC. 

What Would Invoking the Insurrection Act Mean? 

The Insurrection Act is the main exception to the Posse Comitatus Act’s prohibition on utilizing federal troops to police the American people. The Insurrection Act permits the President to “call out” regular armed forces for domestic law enforcement purposes in three scenarios:  

1. When a state governor requests assistance in suppressing an insurrection against the state’s government, the President may send armed forces to assist state and local agencies.
2. The President may act without a request from the state when the President finds “unlawful obstructions, combinations, or assemblages, or rebellion against the authority of the United States make it impracticable to enforce the laws of the United States by the ordinary course of judicial proceedings.”
3. The President may call out forces to quell “any insurrection, domestic violence, unlawful combination, or conspiracy” if enforcement of state or federal laws is hindered or if federal law is opposed or obstructed. 

The last time the Insurrection Act was invoked was in 1992, when then-President George H.W. Bush sent active-duty federal troops into Los Angeles following the riots that broke out after the acquittal of four white officers in the assault of Rodney King. Because President Trump did not invoke the Insurrection Act in his June 7 order, his deployment of 700 United States Marines is unlawful.  

Martial Law 

Although neither the US Constitution nor federal law explicitly define or authorize martial law, judicial precedent has acknowledged its existence as a potential governmental response in times of extreme emergency, subject to constitutional limitations and judicial review.  

Martial law refers to the temporary takeover of government functions by the military. It is permitted only when civilian authorities cannot effectively maintain order or ensure public safety, temporarily suspending all normal civilian government operations. Martial law can be declared during times of war, insurrection, widespread civil unrest, or various national emergencies. While martial law has been declared at both the federal and state levels by both state governors and President Abraham Lincoln during the Civil War, any actions taken under that authority must still comply with the Constitution. 

The Posse Comitatus Act, the Insurrection Act, and case law further clarify the limits of martial law. Its imposition is still subject to judicial review, and the President cannot constitutionally suspend rights like habeas corpus or override civil courts without the consent of Congress.  

Martial law declarations can result in the restriction or suspension of civil liberties, including habeas corpus (detainment without formal charges), First Amendment freedom of speech (censorship), freedom of assembly (gathering prohibitions), and due process (military trials). These intrusions raise concerns about executive overreach and erosion of checks and balances. Yet, the Supreme Court has emphasized that even in times of emergency, “[t]he Constitution does not subject this lawmaking power of Congress to presidential or military supervision or control.” In other words, the Constitution provides that, even in times of emergency, the protection of civil liberties cannot be entirely revoked.  

What Are the Legal Implications of Martial Law, and When Is It Justified?

The Supreme Court has clarified that martial law declaration is appropriate only in cases of “actual necessity,” where civilian government cannot function due to extreme emergency. Additionally, “[m]artial rule can never exist where the courts are open, and in the proper and unobstructed exercise of their jurisdiction. It is also confined to the locality of actual war.” What constitutes an extreme emergency justifying a martial law declaration varies, but it is understood that its imposition is reserved for the most extreme or severe circumstances. It must only be used as a last resort.  

Martial law has been declared several times in American history, most recently at the state level, where Governor J. Millard Tawes proclaimed it in 1963 over Cambridge, Maryland, in response to violent racial riots between civil rights activists, police, and segregationists. The most recent declaration by the federal government occurred in Hawaii. This period lasted from December 7, 1941, following the bombing of Pearl Harbor, to October 24, 1944, when civilian rule was restored. 

Why Does Understanding the National Guard and Martial Law Matter? 

President Trump does not possess unlimited power to deploy federal troops against US citizens or residents. Still, the June 2025 Ninth Circuit decision extended broad discretion to President Trump in declaring a national security emergency. Courts have consistently reaffirmed, however, that civilian authority must remain intact where it is still functional and that constitutional protections do not vanish during emergencies. Any president’s deployment of the National Guard must be legal, narrowly applied to address specific, extreme threats, and grounded in actual necessity — not mere political convenience. As California confronts President Trump’s manufactured crisis, using the National Guard must first be constitutional and, once deployed, must respect constitutional guardrails. 

The League is firmly committed to the right to peacefully protest. First Amendment rights are foundational to our democracy, and it is critical that we stand united in defending unconstitutional efforts to suppress the voices of the people. Federalizing a state’s National Guard without the consent of the governor in response to a peaceful protest is another extreme escalation in the ongoing attack on our democracy.   

Post-Script: DC and the National Guard 

The threat of illegal National Guard occupation is not limited to states. The District of Columbia is home to almost 700,000 Americans who have no representation in Congress beyond a single non-voting delegate, and no rights of statehood. DC’s limited degree of local control is thanks to the District of Columbia Home Rule Act, first enacted in 1973, which still allows Congress to override local laws and grants the president certain authority to take over the city police. 

While the Home Rule Act provides some local autonomy, DC residents do not have the same rights as citizens of other states when it comes to governance. Put simply, they are taxed without representation. Among the powers the federal government retains over DC, is the command of the National Guard. Unlike other state governors, the Mayor of Washington, DC does not command the National Guard; Command is directly held by the President of the United States through the Secretary of Defense. 

Since August 11, 2025, Washington, DC, has been occupied by National Guard forces comprised of the DC National Guard and other states’ guards. The basis of this deployment is a claimed “emergency,” though whether such an emergency exists is highly questionable. The occupation is another reason why DC statehood is necessary to ensure equal rights for DC residents and prevent an abusive occupation of their home city. The League believes in DC statehood and condemns the occupation as an abuse of power and the beginnings of a militarized state. 

A further blog explaining the federal takeover of DC and the need for statehood will soon follow.