The Posse Comitatus Act is a nearly 150-year-old federal law that limits the U.S. military’s role in enforcing domestic laws. At its core, experts say the law reflects America’s long-standing belief that law enforcement should remain in civilian hands, separate from military power.
President Donald Trump has tested the law's limits in the first few months of his second term, as he expands the footprint of the U.S. military on domestic soil.
