Marines in Los Angeles

What are the Marines and troops from the National Guard actually doing in Los Angeles?

While President Trump and other Republicans have insisted the situation in Los Angeles would have deteriorated much faster if not for the intervention of the federal government, the impact of the Department of Homeland Security and the National Guard is the source of heated debate.
“If I didn’t ‘SEND IN THE TROOPS’ to Los Angeles the last three nights, that once beautiful and great City would be burning to the ground right now,” Trump posted on Truth Social early Tuesday.

Fact check: On the ground, federal authorities from the National Guard and DHS have primarily stood in front of federal buildings, blocking the entrances to the downtown immigration detention center and a federal courthouse from protesters. They have not taken to city streets to quell protests. Aside from a clash with demonstrators early Sunday afternoon — where DHS officers and National Guardsmen used riot shields, pepper balls, tear gas and flash-bangs to push a crowd away from the detention center — they have largely let local law enforcement responds to the protests.