Congress passed the National Emergencies Act in 1976.
The thought was: In a crisis, the legislative process could be slow and clunky. The ability to declare a national emergency gave the president broad powers to respond quickly and efficiently when necessary.
George W. Bush declared 13 emergencies and Obama declared 12, most of which are still active today. Bill Clinton declared 17 national emergencies; six are still active. Ronald Reagan declared six and George H.W. Bush declared four. These have since been revoked.
The first declaration came from Jimmy Carter during the Iran hostage crisis, blocking Iranian government property from entering the country.
The state of emergency expires after a year unless the president renews it.
With President Trump’s declaration, there are 32 national emergencies active in the United States.
controversial uses of the declaration
Franklin Roosevelt’s internment of people of Japanese descent during World War II and George W. Bush’s torture program after the 9/11 terrorist attacks are examples of controversial uses of the Act.
Justice Robert Jackson wrote the dissenting opinion (the opinion that didn’t agree with the decision by the Court) in the 1944 Supreme Court ruling that upheld the internment of Japanese Americans. He said each emergency power “lies about like a loaded weapon, ready for the hand of any authority that can bring forward a plausible claim of an urgent need.”