Can Donald Trump use emergency powers to build a southern-border wall?

By S.M. | NEW YORK

ON JANUARY 8TH, in a prime-time address from the Oval Office, Donald Trump repeated his case for building a “physical barrier” on America’s border with Mexico. Erecting a 1,000-mile-long wall to stem the influx of illegal migrants has been a core objective of Mr Trump’s presidency since the early days of his campaign in 2015. Nearly two years after he took office, his project remains stuck at the conceptual phase. But a budgetary showdown with Democrats in the House of Representatives has given Mr Trump a context in which to renew the fight. The president refuses to sign a bill re-opening the federal government unless Congress gives him $5.7bn toward the construction of a border wall. With negotiations at an impasse, on January 6th Mr Trump threatened to “declare a national emergency” and circumvent Congress if lawmakers do not act on his request in “the next few days”. Can the president use emergency powers to fulfil his campaign promise?

Possibly. But the path ahead, should Mr Trump take this route, will be bumpy. Presidents do have wide discretion to declare national emergencies and take unilateral action for which they ordinarily need legislative approval. A “latitude”, John Locke wrote in 1689 (and his writings influenced the US constitution), must be “left to the executive power, to do many things of choice which the laws do not prescribe” since the legislature is often “too slow” in an emergency. American presidents have, for example, suspended the constitutional guarantee of habeas corpus (Abraham Lincoln during the Civil War), forced people of Japanese descent into internment camps (Franklin Delano Roosevelt during the second world war) and imposed warrantless surveillance on Americans (George W. Bush after the September 11th attacks). With some notable exceptions, including when the Supreme Court baulked at Harry Truman’s seizure of steel mills during the Korean War, the judiciary has usually blessed these actions. In addition, Congress has passed dozens of laws—New York University law school’s Brennan Centre for Justice has catalogued 123—giving presidents specific powers during emergencies.