The latest test of President Donald Trump’s powers starts next week in California.

That’s when a federal judge will weigh whether the Trump administration violated a nearly 150-year-old law when it deployed thousands of National Guard and 700 active-duty Marines to Los Angeles this summer against the wishes of the state’s governor and the city’s mayor.

The bench trial will begin Monday in California, where Senior U.S. District Judge Charles Breyer will be asked to decide whether Trump had overstepped the Posse Comitatus Act of 1878, which forbids the U.S. military from acting as a domestic law enforcement arm except under the most extraordinary circumstances. The judge is also expected to hear arguments from both sides about the definition of a “rebellion.”

The stakes in the case are hi

See Full Page