The lawsuit will seek to set aside the president’s order calling up troops in response to protests that spread over the weekend.

President Donald Trump threatened Monday to arrest Gov. Gavin Newsom, a striking example of Trump attacking a fellow elected official just as National Guard troops deployed in Los Angeles amid protests over immigration actions .

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.