“The district court has no authority to usurp the president’s authority as commander in chief,” Kelly said in an emailed statement to the Southern California News Group. “The president exercised his lawful authority to mobilize the National Guard to protect federal buildings and personnel in Gavin Newsom’s lawless Los Angeles.”

What the judge rules, and the likely appeals that follow, may alter decades of understanding about the roles of governors and the White House in quelling domestic unrest.