Congress Must Clarify the National Guard’s Section 502 Legal Authorities

Mark Nevitt is currently an associate professor of law at Emory University School of Law, and previously served as a Navy judge advocate general and tactical jet aviator with assignments around the world.

Historically, the United States’ 54 National Guard units—the Guards of 50 states and four territories—have been deployed domestically under three distinct legal authorities. But there is now a comparably new fourth authority under Title 32—Section 502(f)(2)(A). This fourth authority has emerged as a tool to deploy out-of-state National Guard members across the United States. It could potentially be used as a loophole around the Posse Comitatus Act, which prohibits the military from being used in a law enforcement capacity. What is more, Section 502(f)(2)(A) could create a national security showdown if an outside National Guard unit were deployed to another state without that host state’s consent.

Background on National Guard Authorities

Understanding the precise scope of the Guard’s legal authorities is important, because Posse Comitatus Act restrictions—which prohibit the military from being used in a law enforcement capacity—generally do not apply to the National Guard (or the Coast Guard). The National Guard has legal authorities that go beyond those of federal military forces. Historically, the Guard may be deployed under three traditional authorities:

1. State Active Duty status: The Guard carries out state missions under state command and control using state funds. Here the U.S. president and federal government are not directly involved, although the Guard can work closely with federal military forces that are jointly responding to a natural disaster or providing defense support to civil authorities.
2. Title 10 status: The Guard is federalized under the Insurrection Act and carries out a federal mission under federal command and control using federal funds. Insurrection Act invocations are rare, but have occurred a few times in the past century; the last time the Guard was federalized was during the Los Angeles riots in 1992.
3. Title 32 status: The Guard operates in a hybrid status, performing federal missions using federal funds while remaining under state command and control. This authority was widely used throughout the COVID-19 crisis, the largest domestic military deployment in modern U.S. history.

Section 502: Murky Legal Authorities in Need of Clarification

The scope of these three authorities is well understood, but new applications of Section 502(f)(2)(A) have been added to the legal mix and merit closer analysis. 502(f)(1) authorizes the secretary of the army or air force to order a member of the National Guard to “perform training or other duty.” Section 502(f)(1) was used to activate Guard members for airport security after 9/11.

In the aftermath of Hurricane Katrina, Congress added 502(f)(2)(A) in the 2007 defense spending bill to expand the definition of “other duty” to allow National Guard members to support “operations or missions undertaken by the member’s unit at the request of the president or Secretary of Defense.”

This provision was added to address the federal government’s many shortcomings in responding to major disasters. It is difficult to disaggregate the request provision from its intended purpose: to aid victims of natural disasters and facilitate defense support for civil authorities. In a move that was heavily criticized by Washington, D.C., Mayor Muriel Bowser and legal scholars alike, Attorney General William Barr used this provision to request outside National Guard support from 15 state governors to deploy to the District of Columbia to quell civil unrest in the summer of 2020.

Using 502(f)(2)(A) authorities in such a manner can potentially circumvent the Insurrection Act and Posse Comitatus Act. The Insurrection Act has been the statutory mechanism to suppress civil unrest since the nation’s founding. Section 502 requires further clarification to minimize widespread risk of abuse.

In a letter to President Trump, Mayor Bowser requested that he “withdraw all extraordinary federal law enforcement and military presence from Washington, D.C.” Bowser was specifically concerned that these external National Guard troops were operating outside of established police and incident chains of command, leading to additional and dangerous confusion.

In response to the letter from Mayor Bowser, Barr stated:

At the direction of the President, the Secretary of Defense . . . requested assistance from out-of-state National Guard personnel, pursuant to 32 U.S.C. § 502(f), which authorizes States to send forces to assist the “support of operations or missions undertaken by the member’s unit at the request of the President or Secretary of Defense.”

Under Barr’s reasoning, these out-of-state troops were given broad responsibilities:

Consistent with the President’s direction, the Secretary of Defense assigned to out-of-state National Guard personnel the mission of protecting federal functions, persons, and property within the District of Columbia. That mission includes the protection of federal properties from destruction or defacement . . . protection of federal officials, employees, and law enforcement personnel from harm or threat of bodily injury; and protection of federal functions, such as federal employees’ access to their workplaces, the free and safe movement of federal personnel throughout the city, and the continued operation of the U.S. mails.

While 502(f) authorities have only been invoked in such a manner once—in 2020—the lack of clarity over what constitutes “other duty” opens the door for potential abuse.

Applying 502 Broadly Is Troubling from a Legal & Policy Perspective

First, there is no evidence that Congress, in passing and amending 502(f), envisioned the president using the National Guard in such an expansive manner. Section 502(f) is in part of the U.S. Code titled “Required Drills and Field Exercises.” Deploying to enforce the law is neither a “field exercise” nor a “training drill.” To interpret 502(f) so capaciously is overreach. As written, the statute does not clearly envision massive, out-of-state Guard deployments. To paraphrase Justice Antonin Scalia, Congress does not normally “hide elephants in mouseholes.” And the Supreme Court reaffirmed this reasoning in 2022 in West Virginia et al. v. Environmental Protection Agency et al. Here, the courts held that it would interpret statutory language “in [its] context and with a view to [its] place in the overall statutory scheme.”

Second, using 502(f) authorities undermines state sovereignty and could set the stage for a constitutional showdown if, for example, Blue State A objects to the presence of Red State B’s troops deployed under this authority. Regardless of the legality of such an extraordinary order, having out-of-state military troops outside the established chain of command could lead to operational mishaps and would breed confusion—concerns Mayor Bowser highlighted in 2020.

Imagine a situation where the president targets sanctuary cities and desires a Blue State city to aggressively enforce immigration laws. The state governor is not willing to use its National Guard to take on this unorthodox mission. For political reasons, the president chooses to not federalize the Blue State National Guard under the Insurrection Act; the Insurrection Act is a legal authority that would squarely place the Guard unit under federal command and control. Acting instead under the auspices of the 502(f) authority, the president requests Red State National Guards to perform “other duty”—in this instance, federal immigration law enforcement. Neighboring states more loyal to the president help. What if the Blue State governor refuses to allow the outside National Guard into her state? An analogous situation played out in 2020, when D.C. Mayor Bowser objected to outside National Guard troops being deployed to the nation’s capital. Washington is unique in that it is legally a federal enclave (without voting representation in Congress) and a nonstate jurisdiction.

Third, a White House request under 502(f) authorities for governors to support nontraditional missions would further divide the nation and increasingly politicize the military—a trend that should be resisted at all costs. In 2020, the first Trump White House asked 15 governors to deploy to D.C. as part of the civil unrest mission. Four governors refused. The second Trump administration could use the 502(f)(2)(A) authority as a crude political litmus test to determine which governors are truly loyal to the president’s political agenda. It is worth emphasizing that, as noted, such an effort would only further divide the nation and politicize the military. This is a growing concern in light of the secretary of defense’s actions to fire the nation’s most senior military leaders and Judge Advocate General Corps attorneys.

Potential Reform

Congress should clarify the precise scope of 502 authorities to rein in the potential for future abuse. In 2022, Representative Mikie Sherrill (D-NJ) introduced an amendment to 502(f) to require the consent of the “chief executive of each State [or territory] in which such operations or missions shall take place” prior to outside National Guard units operating in the state, territory, or District of Columbia. To the frustration of many, the Biden administration opposed this amendment “because it would permit non-Federal officials to disapprove use of National Guard personnel.”

Ideally, Congress should add a clause to define “training or other duty” that encompasses support for Stafford Act major disasters or other missions directly related to defense support for civil authorities. And the statute should clarify that any request still requires the consent of the receiving state governor (or D.C. mayor) as a legal prerequisite for sending one state’s National Guard unit to a host state—similar to the innovative 2022 Sherrill amendment.

The National Guard is not a political football. Nor, as Joseph Nunn of the Brennan Center has noted, is Section 502(f) a blank check. Congress should clarify what it means by “other duty” and not wait for a national security showdown to unfold.

About the Commentary Series

In February 2024, the Center for a New American Security (CNAS) launched a project on federalism and national security. This portfolio has taken shape under the CNAS Securing U.S. Democracy Initiative. Recognizing that the 21st-century United States increasingly relies on its system of federalism to rebalance the centers of power and authority across a range of public policy issues, the Securing Democracy Initiative has developed a body of work focused on states’ authorities, roles, and responsibilities that relate to national security functions. Increasing reliance on the U.S. federalist system of government presents both challenges and opportunities for strengthening national security. This commentary series and the December 2024 report Stress Testing State Power: When Governors and Presidents Diverge on Matters of National Security are components of this research effort.

Each commentary in this series explores a current trend or dynamic in modern uses and authorities of the National Guard. Expert authors explore how the Guard is currently being used and will be increasingly called upon in years ahead. Authors provide recommendations for modernizing and clarifying legal authorities for National Guard deployment, and for legislative action at the state and federal levels.

The CNAS project on federalism and national security is made possible with the generous support of the Democracy Innovation Fund, Defending Democracy Together Institute. As a research and policy institution committed to the highest standards of organizational, intellectual, and personal integrity, CNAS maintains strict intellectual independence and sole editorial direction and control over its ideas, projects, publications, events, and other research activities. CNAS does not take institutional positions on policy issues, and the content of CNAS publications reflects the views of their authors alone. In keeping with its mission and values, CNAS does not engage in lobbying activity and complies fully with all applicable federal, state, and local laws. CNAS will not engage in any representational activities or advocacy on behalf of any entities or interests and, to the extent that the Center accepts funding from non-U.S. sources, its activities will be limited to bona fide scholastic, academic, and research-related activities, consistent with applicable federal law. The Center publicly acknowledges on its website annually all donors who contribute.