Can Trump send the National Guard to cities around the US?

The administration of US President Donald Trump has ordered National Guard troops to Portland, Oregon, and to Chicago to suppress protests and bolster immigration enforcement. National Guard were also deployed in recent months to Los Angeles and Washington. Below is a look at the president's legal authority for using the military in US cities, which runs counter to the country's traditions. A federal law called the Posse Comitatus Act generally restricts the use of the US military for domestic law enforcement purposes. This 1878 law embodies a long-held American belief that involving the military in civilian affairs is a threat to personal liberty. The National Guard is a reserve force that can be activated by and put under the command...