In Trump 2.0, most tariffs were imposed under IEEPA. With the Supreme Court perceived to be on the verge of ruling the tariffs unconstitutional, it’s of interest to see what the implications would be.

According to PNC Financial Services Economic Research, eliminating the IEEPA tariffs would at least in the short term reduce the realized effective tariff rate:

Source: PNC Financial Services.

Certain commentators (e.g. Heritage Foundation) have argued that a Supreme Court strikedown would not change overall tariff levels, as Trump could implement tariffs under different authorities. Here is a tabulation of the other trade authorities.

Source: PNC Financial Services.

I think what’s clear is that, given there’s no ongoing US balance of payments crisis, removal of IEEPA tariffs, and the possibility of imposing new ones, would have a short term impact.

Elimination of IEEPA tariff authority would have heightened impact in the context of Trump’s impulsive threat to tariff European countries rejecting Trump’s claim on Greenland. No longer could he threaten country-specific tariffs on a whim.