Which of Trump's tariffs could the US Supreme Court strike down?

THE U.S. Supreme Court holds oral arguments on Wednesday over the legality of President Donald Trump's tariffs imposed under a law called the International Emergency Economic Powers Act, or IEEPA, that never previously was used for such a purpose.

AI Brief

Trump's use of the IEEPA law to impose tariffs is being challenged for legality, as it was never used this way before.
Tariffs under IEEPA target fentanyl trafficking, trade deficits, and political actions; other tariffs use different legal bases.
Tariffs under other laws (Sections 232, 201, 301) on strategic sectors and unfair trade practices are not part of the case.

Trump's administration is hedging its bets by shifting its tariff push to other time-tested legal authorities, including tariffs imposed to protect strategic sectors on national security grounds and country-specific tariffs to combat unfair trade practices.

Here is a rundown of the Trump tariffs at issue in the Supreme Court case and those unaffected by the eventual decision by the nine justices. (Tariff rate given below, followed by assessed tariff collections listed for calendar year 2025 through September 23, before the government shutdown halted updates of U.S. Customs and Border Protection agency data.)

TARIFFS THAT FALL UNDER IEEPA

Trump's duties invoked under IEEPA fall into three categories: those related to illegal trafficking of the often-abused painkiller fentanyl, so-called reciprocal tariffs on all trading partners that are aimed at reducing the U.S. trade deficits, and punitive tariffs imposed on countries for non-trade political reasons.

FENTANYL-RELATED TARIFFS

- China and Hong Kong, 10% reduced from 20%, US$28.9 billion.

- Mexico, 25% on goods not compliant with the United States-Mexico-Canada Agreement, or USMCA, on trade, US$5.7 billion.

- Canada 25% on non-USMCA compliant goods, 10% threatened additional tariff, US$2 billion.

RECIPROCAL TARIFFS:

- Rates from 10% to 50% imposed on goods from all trading partners except Russia. Largest source of IEEPA tariff revenue, US$51.6 billion.

- Numerous trade partners have reached agreements with the United States to reduce tariff rates from higher levels, including the European Union, Japan and South Korea at 15%, and several southeast Asian countries at 19% to 20%. U.S. officials have said these agreements are expected to continue regardless of the Supreme Court's decision.

PUNITIVE TARIFFS

- Brazil, 40% in addition to 10% reciprocal tariff, for the country's prosecution of Trump ally and former president Jair Bolsonaro, US$292 million.

- India, 25% in addition to a 25% reciprocal tariff, over its purchases of Russian oil, US$274 million.

TARIFFS NOT AT ISSUE BEFORE THE SUPREME COURT

Tariffs imposed using a legal authority other than IEEPA include those under Section 232 of Trade Expansion Act of 1962 and Sections 201 and 301 of the Trade Act of 1974.

SECTORIAL DUTIES

Sectoral duties under Section 232 on national security grounds:

- Steel 50%, $4.8 billion; aluminum, 50%, US$3 billion; autos 25%, US$18.3 billion; auto parts 25%, US$7.6 billion; copper 50%, US$513.8 million; timber and lumber, kitchen/bathroom cabinets and upholstered furniture 10% to 50%, started October 14; heavy trucks, 25% started November 1.

- Section 232 tariff investigations underway cover the following sectors: semiconductors and derivative products, pharmaceuticals and ingredients, processed critical minerals, commercial aircraft and jet engines, unmanned aircraft and parts, wind turbines, polysilicon and derivative products, robotics and industrial machinery, medical equipment, medical consumables and personal protective equipment.

UNFAIR TRADE PRACTICES

Unfair trade practices duties under Section 301:

- Trump's first-term tariffs on Chinese imports of 7.5% to 25%, $35 billion.

- Trump's U.S. port fees on Chinese-built, Chinese-owned and Chinese-flagged ships and 100%-150% tariffs on Chinese-built port cranes imposed under Section 301. These have been suspended for a year as part of a de-escalation agreement between Trump and Chinese President Xi Jinping.

- Trump's proposed 100% tariffs on goods from Nicaragua over the country's labor rights, human rights and rule of law practices under an investigation started by former President Joe Biden's administration.

- Section 301 investigations underway that could lead to new tariffs cover China's efforts to dominate legacy semiconductor production; China's compliance with the "Phase One" trade deal reached with Trump in 2020 and Brazil's "unfair" tariffs, ethanol market access and digital trade policies.

SECTION 201 GLOBAL SAFEGUARD TARIFFS

"Safeguard" duties imposed under Section 201 to protect domestic industries injured by a surge of imports:

- Solar cells and modules 15%, US$434 million. Initiated in 2018 during Trump's first term and set to expire this month unless extended by the U.S. International Trade Commission.