On Wednesday, the Supreme Court will hear arguments on the constitutionality of tariffs that President Donald Trump has imposed under the International Emergency Economic Powers Act (IEEPA). The Trump administration faces several issues in its case, not the least of which is that IEEPA does not mention tariffs, duties, or any synonym in its text. Still, if the administration manages to persuade the Supreme Court that IEEPA grants the president the power to tariff imports, the statute would also grant him the power to tariff exports, which is unconstitutional.
The administration will likely reiterate during oral arguments what it emphasized in its final reply brief: Trump's IEEPA tariffs are not taxes—as all revenue-generating tariffs have been understood to be—but importation regulations and, as such, are constitutional.
