More from the article...

... How it works: The president can declare a national emergency at any time, for almost any reason, without needing to prove a specific threat or get approval from Congress.

- - - The National Emergencies Act of 1976, which unlocks more than 120 special statutory powers, originally included a "legislative veto" that gave Congress the ability to terminate an emergency with a simple majority vote.

- - - But in 1983, the Supreme Court ruled that legislative vetoes are unconstitutional " effectively stripping Congress of its original check, and making it far harder to rein in a president's emergency declarations.

The big picture: Since then, presidents have largely relied on "norms" and "self-restraint" to avoid abusing emergency powers for non-crises, says Elizabeth Goitein, senior director of the Brennan Center's Liberty and National Security Program. ...

[good chart in the article]