The US president says he’s deploying 2,000 troops to Los Angeles amid immigration protests. Here’s what to know

Donald Trump said on Saturday he’s deploying 2,000 California national guard troops to Los Angeles to respond to immigration protests, over the objections of the California governor, Gavin Newsom.

Here are some things to know about when and how the president can deploy troops on US soil.

Generally, federal military forces are not allowed to carry out civilian law enforcement duties against US citizens except in times of emergency.

An 18th-century wartime law called the Insurrection Act is the main legal mechanism a president can use to activate the military or national guard during times of rebellion or unrest. But Trump didn’t invoke the Insurrection Act on Saturday.