In August 2025, following comments from President Donald Trump that his administration needed to “federalize” the District of Columbia and “run it the way it’s supposed to be run,” the administration directed over 2,000 National Guard members from multiple states and the District of Columbia to conduct law enforcement activities in the District, including detaining people and performing armed patrols. The District went to court to challenge this use of the National Guard. In October 2025, the Constitutional Accountability Center filed an amicus brief in support of the District. The district court granted the District’s motion for a preliminary injunction, and the Trump administration appealed to the Court of Appeals for the D.C. Circuit. In May 2026, CAC filed an amicus brief in support of the District on appeal. Our brief addresses two points.

First, the Trump administration has no authority to use troops from the D.C. National Guard to create its own police force. As we explain, the President’s status as the Guard’s commander-in-chief does not allow him to deploy the Guard for whatever purpose he wants. Instead, Congress specified in legislation the conditions under which the Guard may be activated. And the only part of this legislation that the administration has identified to justify its actions is a provision concerning troops’ participation in “drills and parades.” Under this provision, the Guard’s commanding general may order troops to perform “drills, inspections, parades, escort, or other duties” (emphasis added). The administration claims that this reference to “other duties” allows it to use the National Guard as an auxiliary police force. But as we demonstrate, the context surrounding these two words, along with basic principles of statutory interpretation, makes clear that “other duties” refers to other training and ceremonial duties like the ones listed, not to law enforcement powers.

Second, our brief shows that the administration also lacks authority to bring National Guard troops into Washington, D.C., from outside the District to perform law enforcement functions. Here, too, the administration’s argument rests on misreading a few words in a single portion of a statute while ignoring everything surrounding those words. As we explain, the federal statute in question simply enables state National Guard units to obtain federal funding for operations that are separately authorized by other laws. The administration claims instead that it allows President Trump to use a state’s troops for any type of mission he might wish, so long as a like-minded governor lends troops to the effort.

This novel interpretation, we explain, would enable presidents to sidestep numerous laws that place important limits on using the military for law enforcement within the United States. Because there is no legal basis for the administration’s unprecedented use of the National Guard, the court should reject its arguments and uphold the rule of law.