President Donald Trump has publicly contemplated invoking a law that would allow him to use the military for almost unlimited domestic law enforcement nationwide in response to at-times violent protests in Los Angeles over immigration crackdowns.

The National Guard has at times detained protesters in its deployment to Los Angeles, an official said Wednesday, as demonstrations against Immigration and Customs enforcement raids spread to other major cities.

The description could become a rationale for invoking the 1807 Insurrection Act, which would give the president broad authority to use the military to deal with violence.