WASHINGTON — Countries around the world — Canada included — are waiting anxiously as the U.S. Supreme Court considers whether President Donald Trump has the authority to continue using his favoured tariff tool.
No matter which way the court jumps, however, the Trump administration is expected to maintain some level of tariffs on the United States’ trade partners.
“The decision in the Supreme Court would be devastating to our country if we got a negative, devastating if we got a negative decision,” Trump told reporters in the Oval Office Thursday.
The conservative-led U.S. Supreme Court heard arguments Wednesday related to two separate legal challenges of Trump’s use of the International Emergency Economic Powers Act for tariffs.
Trump used the national security statute, better known as IEEPA, to impose his so-called “Liberation Day” tariffs and fentanyl-related duties on Canada, Mexico and China.
Trump’s top Supreme Court lawyer, Solicitor General D. John Sauer, faced pointed questions when he appeared before the court Wednesday. Several justices voiced skepticism about the president’s use of IEEPA to pursue his sweeping tariff agenda.
The justices closely examined the language in the act — particularly the wording about the president’s power to “regulate” imports — to determine whether that allows for Trump’s wide-ranging tariffs.
Liberal and conservative justices pushed Trump’s lawyer to explain why the president would use the law for tariffs when it doesn’t mention the word “tariff” or any of its synonyms.
They also pointed out to Sauer that IEEPA was used repeatedly by prior presidents for things like sanctions, but Trump is the only one ever to use it for tariffs.
Sauer argued that Trump is using IEEPA to regulate foreign commerce rather than raise money — despite Trump’s repeated public claims that the duties are making America rich.
The U.S. Constitution reserves power over taxation and tariffs for Congress. The justices wrestled with the broader implications of handing wide-ranging tariff powers to the president.
Trump appointee Justice Neil Gorsuch suggested that once that power was given to a president, it would be next to impossible for Congress to get it back.
“It’s a one-way ratchet toward the gradual but continual accretion of power in the executive branch and away from the people’s elected representatives,” Gorsuch said.
Despite the pushback in Wednesday’s hearing, conservative majority justices have so far been hesitant to rein in the unprecedented expansion of executive power during the Trump administration.
America’s top court could have until June to issue a ruling but it’s expected to come sooner.
If the court rules against the Trump administration, it likely would nullify the 35 per cent economywide tariffs on Canada. Those duties do not apply to goods compliant with the Canada-U.S.-Mexico Agreement on trade.
Trump’s team has said that if the court rules against him, he would look at other available tools to pursue his massive tariff agenda. A reversal at the Supreme Court would make it harder for Trump to change tariff levels on a whim.
Congress has passed laws over the past century that allow the president some control over tariffs in certain situations — but they all have more restrictions than IEEPA.
Trump might turn to Section 338 of the Tariff Act of 1930, which allows a president to hit countries with tariffs of up to 50 per cent if they’re treating imports from other countries more favourably than products from the United States. Section 338 has never been used by a president before.
Trump also might look to Section 301 of the Trade Act of 1974, which allows a president to take trade action if an investigation finds a trading partner’s policies are unreasonable and discriminatory. But that law requires country-by-country investigations of trade policy before a tariff can be imposed.
Section 122 of the Trade Act of 1974 allows a president to implement tariffs of up to 15 per cent to address large and serious balance-of-payments deficits. Those tariffs can only stay in place for 150 days before they require congressional approval to continue.
The Supreme Court’s decision will not affect Trump’s expanding use of tariffs under Section 232 of the Trade Expansion Act of 1962 — tariffs that are already hammering Canada’s steel, aluminum, automobile, lumber and copper industries.
Trump has indicated he plans to target more industries with these duties.
This report by The Canadian Press was first published Nov. 6, 2025.
— With files from The Associated Press
Kelly Geraldine Malone, The Canadian Press
