On Friday, local activists in Los Angeles (including the president of the California chapter of the Service Employees International Union, or SEIU) mobilized in a series of coordinated protests against raids by Immigration and Customs Enforcement (ICE). These initial “protests” led to clashes and arrests, sparking further protests, riots, and arson throughout the city.

On Saturday, President Donald Trump announced he was deploying 2,000 troops from the California National Guard to quell the riots, against the objections of California Gov. Gavin Newsom, who has called the deployment “purposefully inflammatory” and threatened to sue the administration. Trump and some of his top aides, including Stephen Miller, have decried the rioters as “insurrectionists,” though they have stopped short of formally invoking the Insurrection Act, which would grant the president broad latitude to deploy the military to restore order.

As in 2020 or with the widespread anti-Israel protests last year, both social and traditional...