Can the U.S. Military Be Used to Enforce Immigration Laws?

President-Elect Trump extensively campaigned upon a promise, if elected, to deport the huge influx of illegal immigrants who have surged into the United States during the Biden years. This number is in the millions, as nearly everyone agrees, but no one agrees on the approximation figure. Mr. Trump has promissed to start the effort by deporting the dangerous criminal among them, including members of alien gangs that are sworn to violence and criminality. This is a part of Trump’s effort to “Make America Safe Again.”

But just how does a nation physically deport millions of individuals who are unwilling to self-deport? What kind of federal police force is necessary? Surely, this is the job of U.S. Customs and Border Protection (CBP), and to a much lesser extent U.S. Immigration and Customs Enforcement (ICE). But both of these agencies have limited personnel, and diverting many of them from their border posts to conduct roundups, arrests, and deportations from the interior of the country, is not really feasible without further weakening the borders. So where are the personnel who will do this job?

During his campaign, candidate Trump said he would bring home thousands of overseas-based troops and deploy them to secure the southern border.

Early in his campaign he promissed, “Upon my inauguration, I will immediately terminate every open borders policy of the Biden administration. I’ll make clear that we must use any and all resources needed to stop the invasion, including moving thousands of troops currently stationed overseas.” This was a continuing theme during the campaign and one that resonated strongly with MAGA voters.

Upon his reelection in November, Trump made clear that he would declare a national emergency and use American military personnel to carry out mass deportations of undocumented immigrants.

Since his election victory, President-Elect Trump has reiterated his campaign promise to institute mass deportations beginning on Day One of his presidency.

The political opposition is promising every kind of resistance. The ACLU, for one, has stated, “As we ready litigation and create firewalls for freedom across blue states, we must also sound the alarm that what’s on the horizon will change the very nature of American life for tens of millions of Americans.” Blue State Governors and Mayors have announced resistance. See our article, “Deportations and the Constitution’s Supremacy Clause,” in which we discuss this issue.

The United States has long grappled with the role of the military in enforcing domestic laws, including immigration. Two critical laws often cited in discussions on this issue are the Posse Comitatus Act of 1878 and the Insurrection Act of 1807. Understanding these laws and how they interact with federal immigration enforcement, local government resistance, and the concept of sanctuary cities is essential to grasping the legal framework surrounding the military’s potential involvement.

President-Elect Trump’s proposal to involve the military in immigration enforcement brings renewed attention to the Posse Comitatus Act (PCA).

The Posse Comitatus Act (PCA) was enacted to limit the federal government’s ability to use the military for domestic law enforcement.

Under the PCA, federal troops cannot be used to enforce domestic laws unless expressly authorized by Congress or by the Constitution. However, Congress has regularly made such authorizations, creating exceptions that demonstrate the PCA’s flexibility in addressing specific national security concerns while maintaining its general prohibition on direct military enforcement of domestic laws. Does unlawful mass migration in the millions raise national security concerns? We think it certainly does.

The Insurrection Act also provides an exception to the PCA, allowing the President to deploy the military to enforce laws in cases of insurrection, rebellion, or significant civil disorder. This act has been invoked sparingly in U.S. history, such as during the Civil Rights Movement to enforce desegregation.

The Insurrection Act will likely be invoked to address issues such as any large-scale civil unrest related to immigration. But it will likely also be invoked, pursuant to Trump’s anticipated Declaration of National Emergency, to authorize federal troops to assist in the deportation operations. The Insurrection Act specifically allows for the use of the military to enforce federal law when the President determines that rebellion or similar conditions (i.e. state and local active resistance in sanctuary states and cities) make it “impracticable” to enforce the law through normal means. Of course the use of military troops to assist in deportations will face significant legal and political challenges, but Trump did win resoundingly campaigning on this issue. His Administration will likely consider sanctuary jurisdictions that impede federal immigration authorities as obstructing the enforcement of federal laws. Those individuals, including state and local officials, who actively impede federal law enforcement, could face jail time. If applied to immigration enforcement under Trump’s plan, the Insurrection Act could be used to ully justify the deployment of military forces in areas where local authorities obstruct with federal immigration operations.

Presently, the PCA restricts active-duty military from directly enforcing immigration laws, although they can provide support roles under certain conditions. These current deployments typically involve logistical support, surveillance and construction, rather than direct law enforcement. But this will all change upon the promulgation of a National Emergency Proclaimation, which will allow the military to be used for direct federal law enforcement. Most likely, those in opposition will file court cases challenging the authority, claiming that the national emergency does not exist, or that the proclamation is nothing more than a device to end-run the laws discussed in this article. One strategy the opponents may use is to file a separate lawsuit on behalf of each illegal immigrant, seeking a stay enjoining the federal governmment from deporting the individual petitioner until his or her case can be heard on its merits, and if millions of these cases are filed, the courts will grind to a halt. Whether this happens depends on how quickly appellate courts approve this tactic or order these cases dismissed.

Whatever one’s views illegal immigration may be, the rate at which it has escalated during the Biden years, and the millions of unknown and unvetted persons within our borders, including thousands of violent gang members and thousands of people thought to be enemy military personnel being put in place for terrorism when given the order, certainly appears to us to qualify as a national emergency. Even on a more local level, there are emergencies too: School districts, which are paid through real estate taxes, are being flooded with illiterate immigrant children, while there parents pay nothing to the school districts. Hospitals, which rely on insured and paying patients, are being flooded with impoverished and uninsured illegal aliens. Hotels are being filled by these illegal immigrants (paid out of city funds), causing paying tourists to stay away. Home prices and rents are very high, which really makes no difference as these people arrive with no money, but they have to live somewhere where they will not die from freezing during the winter months, and this is at great cost to cities and towns, which have to divert funds from other necessary purposes. Thus, we believe that a court, being non-partisan and judging this matter solely on its merits, will find that the declaration of a national emergency is reasonable and authoried in these circumstances, thus allowing the military to be used to enforce federal immigration laws and play an active role in the promised deportation operations.