The National Guard is typically brought into American cities during emergencies such as natural disasters and civil disturbances or to provide support during public health crises — when local authorities require additional resources or manpower. There was no indication that was needed or wanted in Los Angeles this weekend, where local law enforcement had kept protests over federal immigration raids, for the most part, under control.

Guard members also almost always arrive at the request of state leaders, but in California, Gov. Gavin Newsom called the deployment of troops “purposefully inflammatory” and likely to escalate tensions. It had been more than 60 years since a president sent in the National Guard on his own volition.

Which made President Trump’s order on Saturday to do so both ahistoric and based on false pretenses and is already creating the very chaos it was purportedly designed to prevent.

Mr. Trump invoked a rarely used provision of the U.S. Code on Armed Services that allows for the federal deployment of the National Guard if “there is a rebellion or danger of a rebellion against the authority of the government of the United States.” No such rebellion is underway. As the governor’s spokesman and others have noted, Americans in cities routinely cause more property damage after their sports teams win or lose.

The last time this presidential authority was used over a governor’s objections was when John F. Kennedy overruled the governor of Alabama and sent troops to desegregate the University of Alabama in 1963. Supporters of states’ rights and segregation howled at the time and, in the usual corners, are still howling about it.

“To the extent that protests or acts of violence directly inhibit the execution of the laws, they constitute a form of rebellion against the authority of the government of the United States,” Mr. Trump wrote in an executive order, which is not a law but rather a memo to the executive branch. Yet the closest this nation has come to such a definition of rebellion was when Mr. Trump’s own supporters (whom he incited, then mostly pardoned) sacked the U.S. Capitol in 2021.