Doctrine Used to Nix Biden Moves Threatens to Undo Trump Tariffs

Standing in the way of President Donald Trump’s new trade war is a hurdle of the US Supreme Court’s own making.

The 6-3 conservative majority reinvigorated the major questions doctrine to strike down a number of Biden administration policies. Now the legal principle could stop Trump’s tariff policy against China, Canada, and Mexico depending on how things play out.

The doctrine directs courts to reject an agency’s interpretation of a statute when it presents an issue of great political or economic significance, unless Congress has clearly authorized it. In targeting tariffs on imports across-the-board, Trump invoked the International Emergency Economic ...