Immigration Policy Brief #191 | Morgan Davidson | August 17, 2025
Summary
As summer draws to an end, President Trump is once again utilizing federal military forces for law enforcement, this time in the nation’s capital. In California, Trump cited immigration protests for the use of the National Guard & ultimately the deployment of U.S. Marines. Now we see the President citing crime & the inability of D.C. Democrats to stop it. President Trump’s coast-to-coast use of federal military force in Los Angeles and Washington, D.C. during 2025 highlights the growing tensions between public safety, constitutional boundaries, and presidential power, raising critical questions about the future of American democracy and civil-military relations.
Analysis
The legal framework governing domestic military force is defined by the Posse Comitatus Act and the Insurrection Act, but Trump’s recent actions reveal the ambiguity of these laws and their potential for executive overreach. The Posse Comitatus Act was signed by Rutherford B. Hayes in 1878 in response to the use of the military as law enforcement during Reconstruction following the Civil War. The act prohibits the U.S. military from enforcing domestic law or acting as law enforcement unless explicitly given permission by Congress or through the Constitution. The Insurrection Act allows the President to deploy military forces to act as law enforcement to “suppress insurrection & repel invasions”. While that wording may seem clear & the situation in D.C. fails to meet those requirements, we still see Trump deploy military forces to act as police in our nation’s capital. With a President eager to utilize military forces as law enforcement across U.S. cities, a complicit Congress, & a Supreme Court that continually affirms the expansion of executive power, it is no surprise to see the military used as police in 2 U.S. cities with Trump wishing to do the same in Chicago & New York.
Trump’s federalization of the California National Guard and deployment of Marines to Los Angeles marked a rare and controversial use of military force against civilian protests, sparking immediate legal challenges. In June 2025, Los Angeles became the first major U.S. city where Trump moved beyond threats and fully exercised federal control over state forces. Citing escalating immigration protests and unrest, Trump federalized the California National Guard and deployed about 700 U.S. Marines under Joint Task Force 51, with an additional 2,000 Guard members placed on standby. California officials immediately challenged the move. Governor Gavin Newsom sued in federal court, arguing that Trump’s order violated the Posse Comitatus Act and trampled on state sovereignty under the Tenth Amendment. A federal judge initially granted a temporary restraining order halting the deployment, but the Ninth Circuit Court of Appeals quickly stayed the decision, allowing the Guard and Marines to remain under federal command while the case proceeded. The episode underscored the unsettled constitutional boundaries around domestic use of the military and deepened partisan divides, with Trump framing the move as decisive leadership while critics warned it amounted to an authoritarian show of force.
In August 2025, Trump declared a “Crime Emergency” under the D.C. Home Rule Act and placed the Metropolitan Police Department under federal control. He ordered roughly 800 National Guard troops into the city and brought in additional units from West Virginia, South Carolina, and Ohio, raising the total force to well over a thousand. While the Guard was officially limited to logistics and support, reports soon surfaced that some units were preparing for armed patrols alongside local police. The deployment immediately drew resistance from city leaders, who noted that crime had already been trending downward and argued that federal intervention undermined D.C.’s fragile self-governance. Civil liberties groups, including the ACLU, warned that the operation blurred the traditional line between civilian law enforcement and military force. Trump, however, defended the move as proof of his resolve to restore order in Democratic-run cities, and he openly suggested that Chicago and New York could be next.
Taken together, the Los Angeles and D.C. interventions illustrate Trump’s willingness to test constitutional limits, generating fierce opposition from state officials, courts, and civil rights organizations. In California, Governor Gavin Newsom immediately positioned himself as Trump’s foil, challenging the federalization of the National Guard in court and warning that the President had crossed a constitutional line. While the courts initially slowed Trump’s actions, the Ninth Circuit’s decision to stay the lower ruling underscored how fragile the guardrails truly are when judicial deference to executive power is the norm. In Washington, D.C., local leaders voiced similar outrage, but their ability to resist was even more constrained. By invoking the D.C. Home Rule Act, Trump sidestepped local autonomy almost entirely, demonstrating how the nation’s capital provides a unique venue for executive power to be flexed without meaningful checks. Civil liberties groups like the ACLU warned that these deployments set a dangerous precedent for the normalization of military involvement in routine law enforcement, a trend that could spread to other cities. At the same time, Trump’s supporters framed both interventions as proof of his strength and his willingness to do what Democrats could not or would not do: “restore order.” The result is a sharp divide in how Americans interpret the same actions, authoritarian overreach to some, decisive leadership to others, with the courts and political institutions increasingly reluctant or unable to resolve the tension.
The precedent set by Trump’s actions risks normalizing the use of military force as a domestic political tool, threatening the balance between civilian governance and military neutrality. By ordering Guard troops and even active-duty Marines into American cities, Trump has blurred the line between soldiers and police in a way that undermines long-standing democratic norms. The civil-military divide, a crucial pillar of American democracy, depends on the military remaining above partisan politics. Yet, Trump has repeatedly cast deployments in explicitly political terms, presenting them as proof of his ability to impose “law and order” where Democratic officials have failed. If left unchecked, these episodes could serve as ready-made blueprints for future presidents who might see military intervention in civilian affairs not as a last resort, but as an acceptable tool of governance. Each deployment chips away at the assumption that law enforcement is local and civilian-led, replacing it with a model in which federal power is backed by troops in uniform. The danger is not simply Trump’s use of force in 2025, but the possibility that his actions will erode constitutional guardrails and normalize the military’s role in policing American streets.
Engagement Resources
- Brennan Center- Understanding Posse Comitatus Act: A good primer on the Posse Comitatus Act & its history.
https://www.brennancenter.org/our-work/research-reports/posse-comitatus-act-explained - Brennan Center- Understanding Insurrection Act: The Brennan Center explores, explains, & suggests reforms for the Insurrection Act.
https://www.brennancenter.org/our-work/research-reports/insurrection-act-explained - Trump Threatens Other U.S. Cities with Use of Federal Military Force : CNN covers Trump’s future plans for other cities including Chicago, New York, & L.A.
https://www.cnn.com/2025/08/12/politics/trump-federalized-dc-crime-home-rule-act-hnk