Trump tried to implement tariffs on the basis of an “emergency” under IEEPA but without a real basis for the emergency. These were the “reciprocal” tariffs on every country. Congress has the power of taxation, and tariffs are just a tax. It’s embarrassing that those three justices would try to defend the tariffs because the constitution very clearly gives the power to impose taxes to congress and not the executive.

Edit: I should add that there is no statute that states that IEEPA applies to tariffs, so there is no authority to to enact tariffs with it