A look at D.C.’s unique history and why presidents can wield control of law enforcement

Some of the more than 2,000 National Guard troops on duty in Washington, D.C., are now armed, part of a crackdown that President Trump once again claimed was needed to help curb crime in the city. While he threatened similar actions in other cities, including Chicago and New York, his power to consolidate law enforcement in the nation’s capital is unique. Deema Zein explains.