159. The Posse Comitatus Act Meets the President's "Protective Power"

How to reconcile Article II and the Posse Comitatus Act with respect to President Trump's federalization of California National Guard troops and deployment of Marines in and around Los Angeles.

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[An edited version of this co-authored post is cross-posted at Just Security.]

President Donald Trump’s controversial federalization of members of the California National Guard and his deployment of at least 700 active-duty Marines to Los Angeles has raised a series of novel, important, and challenging questions about the scope of the Executive Branch’s legal authorities when it comes to domestic use of the military.

On one hand, the Posse Comitatus Act of 1878 generally forbids use of federal armed forces for civilian law enforcement unless a statute specifically authorizes it. Although the Insurrection Act has long been understood to be one such statute, Trump has, quite notably, not invoked it here. On the other hand, the Executive Branch (with a bit of help from the Supreme Court) has long claimed inherent power to use military force unilaterally to “protect federal functions,” including the power to defend federal property and federal personnel from violence. Thus, perhaps the dominant question Trump’s military deployment raises is the shape of the Venn diagram created by these two opposing forces. Are they mutually exclusive? If they overlap, which one prevails? Or put more basically, where does this “protective power” end, and (generally prohibited) law enforcement begin?

In our view, there are three possible answers to this question. On the first view, the protective power can include law enforcement—and overrides the Posse Comitatus Act when it does. On the second, the protective power, as an exercise of Article II authority, cannot be understood to include any typical law enforcement activity—and so such activity is unlawful unless specifically authorized by congressional statute. On the third, the answer is somewhere in between—where the protective power does not generally authorize law enforcement activity, but does when that activity is incidental to the protection of federal property and personnel (such as arresting individuals while they are attacking a federal building).

As we explain in the discussion that follows, we think that there are strong arguments to be made in support of both the second and third options—but not the first. More to the point, we think Congress has been far more clear than is widely believed about what its view is—in a way that calls into at least some question what the Trump administration has thus far used federal military forces for in and around Los Angeles.

I. Protective Power as an Exception to Posse Comitatus

The Posse Comitatus Act itself bars domestic use of the military “to execute the laws” “except in cases and under circumstances expressly authorized by the Constitution or Act of Congress.” Obviously, nothing in the Constitution “expressly authorize[s]” the President to protect federal functions. Instead, such an Article II power is, at best, implicit—derived from some combination of the Vesting Clause and the Take Care Clause.

By itself, that ought to resolve any debate over whether any protection of a federal function is therefore exempted from the Posse Comitatus Act’s ban, whether it involves law enforcement or not. But there is also plenty of Founding-era history supporting the view that Congress, and not the President, would have broad power to define the circumstances in which the military could be used domestically. Indeed, the Insurrection Act itself derives from statutes Congress enacted in 1792 and 1795, both of which reflected the universal understanding at the time that the President could use military force “to execute the laws of the union” only if Congress had specifically authorized him to do so.

And, to its credit, the Department of Justice in the current litigation over the Los Angeles deployments has seemingly embraced this view. As it argued in its very first brief:

Plaintiffs’ objection based on the Posse Comitatus Act is equally misdirected. Neither the National Guard nor the Marines are engaged in law enforcement. Rather, they are protecting law enforcement, consistent with longstanding practice and the inherent protective power to provide for the safety of federal property and personnel. [emphasis in original]

(See also the most recent brief at p. 29.)

Thus, not only do we find wholly unpersuasive any argument that the protective power overrides the Posse Comitatus Act; we don’t understand that to be the Trump administration’s litigating position, at least thus far.

II. Posse Comitatus as a Law Enforcement Ban

At the other end of the spectrum is the argument that the protective power cannot fairly be understood to include any law enforcement functions—that it does not encompass searches, seizures, arrests, or any other activity similarly characteristic of law enforcement. The Ninth Circuit, for example, has interpreted the Posse Comitatus Act to prohibit any direct participation by the military in actions that “subject civilians to the exercise of military power that is regulatory, proscriptive, or compulsory in nature.” Thus, on this view, even where what might be viewed as law enforcement activity by the military is necessarily incidental to protecting federal buildings or personnel, it is still prohibited without clear congressional authorization.

Congress put at least a thumb on the scale in this direction in 1981—when it enacted what is present-day 10 U.S.C. § 275. Under that provision,

The Secretary of Defense shall prescribe such regulations as may be necessary to ensure that any activity (including the provision of any equipment or facility or the assignment or detail of any personnel) under this chapter does not include or permit direct participation by a member of the Army, Navy, Air Force, or Marine Corps in a search, seizure, arrest, or other similar activity unless participation in such activity by such member is otherwise authorized by law.

Although this provision is focused on military support for civilian law enforcement agencies, the authoritative House Report is much clearer on how Congress understood the relationship between the protective power and the Posse Comitatus Act:

Certain military activities, although otherwise prohibited by the Posse Comitatus Act, are permissible if expressly authorized by statute. These permissible military actions are specifically defined and are generally restricted to instances involving civil disorders (10 U.S.C. 331–36), disasters (42 U.S. 4401–84 and 1855), and threats to federal property (see letter from Mary C. Lawton, Office of Legal Counsel, Department of Justice, to Deanne Siemer, General Counsel, Department of Defense, March 24, 1978 at 3; see also United States v. Banks, 539 F.2d 14, 16 (4th Cir. 1976). The other specific and “express” statutory exceptions to Posse Comitatus include: (1) 16 U.S.C. 23 and 16 U.S.C. 78 (protection of federal parks); (2) 18 U.S.C. 112(f) and 1116 (protection of foreign officials, official guests, and other internationally protected persons); (3) 18 U.S.C. 351 (crimes against members of congress); (4) 18 U.S.C. 1751 and 3056 (protection against crimes against the president); (5) 22 U.S.C. 408, and 461-462 (enforcement of the neutrality laws); (6) 42 U.S.C. 1989 (execution of warrants relating to certain violations of the civil rights laws); (7) 42 U.S.C. 3756 (loan of services, equipment, personnel and facilities to LEAA [Law Enforcement Assistance Administration]); (8) 43 U.S.C. 1065 (removal of unlawful enclosures from public lands); and (9) 50 U.S.C. 220 (enforcement of the customs laws).

Thus, § 375 was enacted against a backdrop in which the presumption is that activities are prohibited unless they are statutorily authorized. In a note accompanying the first sentence of the above passage, the House Report rules out any notion of a separate Article II authority in reference to the Posse Comitatus Act. The note states in full: “The statute permits constitutional exceptions. However, there are none.” Thus, Congress’s view appears to be that the protective power is not an “exception” to the Posse Comitatus Act; it is defined in such a way so as to not even implicate it.

[Note: The Office of Legal Counsel has relied on the House Report and accompanying Conference Report as authoritative guides for determining the scope of permissible military action and the Posse Comitatus Act.]

III. The Hybrid: Law Enforcement Only as Necessarily Incidental to Protection

Although we generally find Congress’s view satisfying, it raises one puzzle: What about the Supreme Court’s decision in In re Neagle, which held that the President did not need statutory authorization to appoint a deputy U.S. marshal to protect a Supreme Court Justice from an attempted assassination? Even if Deputy Neagle wasn’t exercising “law enforcement” authority when he shot and killed David Terry in defense of himself and Justice Field, it would be a very strange result if he had the power to shoot at Terry, but not to arrest and detain him. The point is not that Deputy Neagle had general law enforcement power; it’s that he had those powers that were necessary to discharge his (valid) duty to protect Justice Field.

We think the 1981 amendment can be read consistently with this view. As the 1981 Conference Report noted,

Nothing in this section, however, limits the inherent authority of military personnel to defend themselves or to protect federal property. Nothing in this chapter adversely affects the authority of the attorney general to request assistance from the department of defense under the provisions of 21 U.S.C. 873(b). The limitation posed by this section is only with respect to assistance authorized under any part of this chapter.

[Update: Further to our point, the above passage might be read even more narrowly as an emergency exception. The House Report states: “Nothing in this section, however, changes the existing exceptions to the Posse Comitatus Act which allow military personnel to protect lives and federal property in emergency situations when they are involved in the performance of a lawful activity. For example, under current law, and under this proposal, nothing prohibits an air force pilot operating military aircraft from protecting him or herself from aggressive or destructive acts of a drug violator while on an authorized mission.” (We thank Chris Mirasola for this point.)]

Consistent with this understanding, long-standing Defense Department policies state that it is permissible for the military to engage in at least some law enforcement activity in the protection of federal government functions:

Permissible Direct Assistance. Categories of active participation in direct law enforcement-type activities (e.g., search, seizure, and arrest) that are not restricted by law or DoD policy are …

Federal military commanders have the authority, in extraordinary emergency circumstances where prior authorization by the President is impossible and duly constituted local authorities are unable to control the situation, to engage temporarily in activities that are necessary to quell large-scale, unexpected civil disturbances because:
…

When duly constituted Federal, State, or local authorities are unable or decline to provide adequate protection for Federal property or Federal governmental functions. Federal action, including the use of Federal military forces, is authorized when necessary to protect Federal property or functions. [emphasis added].

The key, in our view, is the bolded language. The question is whether the specific search, seizure, and arrest are “necessary to protect Federal property or functions.” Sending armed troops along with ICE agents on immigration raids can’t possibly meet that test, whereas stationing troops in front of a federal building and authorizing them to arrest those who attack it is. It would also be completely unprecedented to use the protective function to protect enforcement officials—and in a way that entangles the military forces in the very act of law enforcement. As reflected in both the 1981 enactment of § 275 and the Department of Defense’s own long-standing view, the upshot is that law enforcement qua law enforcement is strictly prohibited. Only if the compulsory action is necessary (and incidental) to the protection of federal property or personnel can it be said to have any basis in Article II of the Constitution.

Of course, law enforcement activities can be authorized by other statutes. But we’re not at all persuaded that 10 U.S.C. § 12406 is such a statute. And it would not, in any event, resolve the validity of the deployment of the Marines to this point. Thus, in our view, the central legal question arising out of the use of military force in and around Los Angeles is not whether the troops are engaged in any “law enforcement-like activities,” but whether those activities are strictly necessary (and incidental) to the protection of federal property and functions. Insofar as they are not, we believe they violate the Posse Comitatus Act.

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