If You Can Keep It: The president and the National Guard

President Donald Trump’s decision to send the National Guard to Los Angeles is now up in the air – with a federal appeals court reviewing the case. A lower court has already said Trump acted illegally.

There are strong norms against using active duty military for law enforcement on U.S. soil. What are they? And why do we have them?

For this edition of our weekly politics series, “If You Can Keep It,” we explore how presidents can and can’t deploy U.S. troops domestically.