Opponents of President Donald Trump’s “Liberation Day” tariffs are finally getting their day in the U.S. Supreme Court. And while the justices may not rule for some time, their lines of questioning could offer hints about which way they are leaning in the blockbuster case.
On Wednesday, the high court will hear from the plaintiffs — a dozen Democratic-run states and two sets of private companies — and the Trump administration. Each side will have 40 minutes to make their arguments and then get peppered with questions from the nine justices.
The court then has until the end of its term next July to issue a ruling, although some of the lawyers who brought the initial cases hope it will move faster given the real-world impact the decision will have. “It’s very reasonable to expect that this will be decided before the end of the year, if not much, much more before that,” said Jeffrey Schwab, senior counsel at the Liberty Justice Center, a constitutional rights law firm representing companies in the case.
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Three federal courts have ruled against Trump’s use of a 50-year-old emergency law to impose broad “reciprocal” duties that he then deployed to strike trade deals with the EU, Japan and other partners. The case does not address sectoral tariffs on products like steel, aluminum or autos, which have also been part of negotiations, but were imposed under a different legal authority that is not in dispute.
If the Supreme Court rules that the tariffs Trump announced in April are illegal, will those deals fall apart? We analyze the risks:
United States
Risk assessment: Many legal experts think there is a strong chance the Supreme Court will strike down the duties that Trump imposed under the International Emergency Economic Powers Act (IEEPA), a 1977 sanctions law that empowers Trump to “regulate” imports but does not specifically authorize tariffs.
Not all agree, arguing the conservative-led court is likely to back the Trump administration’s view that the president has broad authority to conduct foreign affairs and that imperative outweighs any concerns about executive branch overreach that the court has expressed in previous cases.
Coping strategy: In the worst-case scenario for the administration, the Supreme Court would strike down all the duties and order it to repay hundreds of billions of dollars in duties paid by companies and individuals.
But even in that scenario, Trump may be able to use other authorities to recreate the tariffs, including Section 122 of the 1974 Trade Act. That provision could allow the president to impose a 15 percent global import “surcharge” for up to 150 days, according to the Cato Institute, a libertarian think tank.
Trump would have to get congressional approval to keep any Section 122 tariffs in place for longer — a tall order even in a Republican-led Congress. However, he might be able to use the provision as a stopgap measure while he explores other options.
Those include Section 301 of the 1974 Trade Act, which he used in his first term to impose extensive tariffs on Chinese goods and recently deployed against Brazil. Unlike IEEPA, which Trump believes merely allows him to declare an international emergency to impose tariffs, Section 301 requires a formal investigation into whether the United States has been harmed by an unfair foreign trade practice.
However, Trump could also just use those investigations — and the implied threat of tariffs — to pressure trading partners like the EU into reaffirming the trade deals they have already struck with him.
Trump could also launch additional sectoral investigations under Section 232 of the 1962 Trade Expansion Act, a provision that allows the president to restrict imports determined to pose a threat to national security. He has employed that measure in his first and second term to impose duties on steel, aluminum, autos, auto parts, copper, lumber, furniture and heavy trucks.
In one variation, he’s used an ongoing investigation into pharmaceutical imports to pressure companies to invest more in the United States and to slash drug prices. He has also used the threat of semiconductor tariffs to prod countries and companies into concessions, without yet imposing any duties.
The Commerce Department has other ongoing Section 232 investigations into processed critical minerals, aircraft and jet engines, polysilicon, unmanned aircraft systems, wind turbines, robotics and industrial machinery, and medical supplies. And, as Trump’s lumber and furniture duties demonstrate, the administration’s expansive definition of national security provides it with broad leeway to open new investigations into a variety of sectors.
By Doug Palmer
European Union
Risk assessment: The European Union isn’t counting on the Supreme Court to save it from Trump’s 15 percent baseline tariff — knowing full well that if U.S. tariffs don’t come through the front door, they’ll come through the window.
“Even a condemnation or a ruling by the Supreme Court that these reciprocal tariffs are illegal does not automatically mean that they fall,” the EU’s top trade official, Sabine Weyand, told European lawmakers recently. “There are other legal bases available.”
Trump invoked IEEPA to impose the baseline tariff on the 27-nation European bloc. But Brussels is more worried about sectoral tariffs that Trump has imposed on pharmaceuticals, cars and steel using other legal avenues — chiefly Section 232 investigations — that aren’t the subject of the case before the Supreme Court.
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Coping strategy: Brussels is in full damage-control mode, trying not to stir the pot too much with Washington and focusing on implementing the deal struck by European Commission President Ursula von der Leyen at Trump’s Turnberry golf resort in Scotland in July — and baked into a bare-bones joint statement the following month.
Crucially, the EU asserts that it has locked in an “all-inclusive” tariff of 15 percent on most exports — so even if the Supreme Court throws out Trump’s universal tariffs it would argue that the cap should still apply. “Even if all IEEPA tariffs are eliminated, the EU would have an interest in keeping the deal,” Ignacio García Bercero, who used to be the Commission’s point person for its trade talks with the U.S., told POLITICO.
The Commission is also still in negotiations with the Trump administration to secure further tariff exemptions for sensitive sectors such as wines and spirits.
The European Parliament, which will need to approve the Turnberry accord, is taking a more hawkish line over what many lawmakers have criticized as the one-sided trade deal with the U.S.: It wants to add a “sunset” clause that would effectively limit the EU’s trade concessions to Trump’s term in office. EU countries have given that idea the thumbs down, however, saying deals that have been agreed must be respected.
The EU has invited Commerce Secretary Howard Lutnick to a meeting of its trade ministers in Brussels on Nov. 24. The focus there will be on reassuring him that the legislation to implement the trade deal will pass, and on fending off U.S. charges that EU business regulation is discriminatory.
By Camille Gijs
United Kingdom
Risk assessment: Should the Supreme Court strike down Donald Trump’s universal tariffs, Britain won’t be off the hook. London may have secured a favorable, 10 percent baseline rate with Washington back in May — but that only goes so far.
That protection does not extend to Trump’s Section 232 steel and auto levies, which remain in place. Under the current deal, Britain gets preferential tariffs on its car exports, as well as a 50 percent reduction to the global steel tariff rate.
If Britain tried to renegotiate its baseline tariffs, the U.S. could quickly retaliate by withdrawing those preferential deals, and take a harder line in ongoing negotiations covering pharma and whisky tariffs.
Coping strategy: The U.K. is pressing ahead with its negotiations with the Trump administration on other parts of the deal — despite the ongoing court case. British officials fly out to D.C. in mid-November to push forward talks, shortly before Trade Representative Jamieson Greer is due in London on Nov. 24.
“I don’t think the U.K. or others would attempt to renegotiate in the first instance — we might even see some public statements saying we plan to honour the deal,” said Sam Lowe, British trade expert and partner at consultancy firm Flint Global. “There’s too much risk in trying to reopen it in the first instance, given it could antagonise Trump.”
Meanwhile the U.K. is seeking to strengthen its trade ties with other nations. It struck a free trade agreement with India over summer, is renegotiating aspects of its trading relationship with the European Union and hopes to close a trade deal with a six-nation Gulf economic bloc including Saudi Arabia and the United Arab Emirates in the coming weeks.
The U.K. is expected to maintain its current deal with the U.S., even if legal challenges were to weaken Trump’s wider tariff regime.
By Caroline Hug
China
Risk assessment: Chinese leader Xi Jinping exited his meeting with Trump in South Korea last week with a U.S. commitment to cut in half the 20 percent “emergency” tariff imposed in March to punish Beijing for its role in the U.S. opioid epidemic. A possible ruling by the Supreme Court that overturns the residual “emergency” tariffs on Chinese imports — the remainder of the fentanyl tariff and the 10 percent “baseline” levy added in April — would leave Beijing with an average 25 percent tariff rate.
The judges will test the administration’s position that its IEEPA tariffs are legally sound because they constitute a justified regulation of imports. But a blanket ruling on the levies on Chinese imports isn’t guaranteed.
“The Supreme Court is likely to make a binary ruling — the court might decide the trade deficit tariffs are illegal, but the fentanyl tariffs are lawful,” said Peter Harrell, former senior director for international economics in the Joe Biden administration.
The Chinese embassy declined to comment on how Beijing might respond to a SCOTUS ruling in China’s favor. But it would mark a symbolic victory for the Chinese government whose Foreign Minister Wang Yi has described them as an expression of “extreme egoism.”
Coping strategy: Celebration in Beijing about a possible revocation of any of these tariffs may be short-lived. That’s because Trump can wield multiple other trade weapons even if the Supreme Court deems the tariffs unlawful.
His administration signaled that it’s priming potential replacements for the IEEPA tariffs with the Office of the U.S. Trade Representative’s announcement last week of Section 301 probes of Beijing’s adherence to the U.S.-China Phase One trade deal in Trump’s first term. It is also undertaking Section 232 probes — geared to determine national security threats — of Chinese-dominated imports including pharmaceuticals, critical minerals and wind turbines.
“There’s ample opportunity for the Trump administration to use other legal instruments in the event that the IEEPA tariffs get struck down,” said Emily Kilcrease, a former deputy assistant U.S. trade representative during Trump’s first term and under Biden. The 301 investigation into the Phase One deal is already active, and “will allow them to be fairly quick in responding in the event that the Supreme Court rules against the administration,” Kilcrease said at a Center for a New American Security briefing.
By Phelim Kine
Canada
Risk assessment: It’s a bit of a lose-lose situation for Canada.
Trump pre-emptively blamed a Canadian provincial government for weaponizing Ronald Reagan in an ad to influence the SCOTUS ruling. The 60-second spot launched on U.S. networks on Oct. 16 to bring an anti-trade war message to Republican districts rather than to nine Supreme Court justices. It riled Trump enough that he ended trade talks eight days later. Then he vowed to increase tariff levels by 10 percent in retribution.
If the court sides with Trump, it will justify an impulse to use IEEPA to raise rates higher without a need for findings or an investigation. And if the court rules against the president — Ottawa will have to prepare for more of Trump’s fury over the ad.
The U.S. increased the IEEPA tariff rate on Canada to 35 percent from 25 percent in July, citing a failure to crack down on fentanyl trafficking across the northern border. This 35-percent rate excludes the promised 10-percent retributive increase — an executive order hasn’t been released. It’s unclear which legal authority Trump will use if his stated reasoning is to punish Canada over an ad about Reagan’s warning about protectionism.
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Prime Minister Mark Carney has called the IEEPA tariffs “unlawful and unjustified.” And he’s been able to play down the threat, for now, by reminding Canadians that these “fentanyl tariffs” have a carve-out for goods covered under the United States-Mexico-Canada Agreement (USMCA). Carney regularly says 85 percent of Canadian exports enter the U.S. tariff free. Section 232 tariffs on industry have hit the economy harder than the IEEPA tariffs.
Coping strategy: Canada is frantically pursuing trade diversification coupled with a high-level charm offensive while its trade negotiators try to limit the scope of the upcoming review of the USMCA to minimize U.S. tariff exposure.
“Our priorities are to keep the review as targeted as possible, to seek a prompt renewal of the agreement, while securing preferential market access and a stable and predictable trading environment for Canadian businesses and investors,” Canadian Ambassador to the U.S. Kirsten Hillman recently told a parliamentary committee.
Carney has, meanwhile, apologized to Trump for the Reagan ad.
By Zi-Ann Lum
Mexico
Risk assessment: Trump has hit Mexico, the largest U.S. trading partner, with multiple tariffs since taking office. Those include a 25 percent duty imposed under IEEPA to pressure the country to do more to stop fentanyl and precursor chemicals — as well as illegal immigrants — from entering the United States.
Trump softened the blow by excluding goods that comply with terms of the U.S.-Mexico-Canada Agreement from the new IEEPA duties. That has encouraged more and more companies to fill out paperwork to claim the exemption.
About 90 percent of Mexican goods entering the U.S. now have the necessary USMCA documentation, compared to around 60 percent last year, said Diego Marroquín, a fellow in the Americas program at the Center for Strategic and International Studies.
Still, U.S. customs officials report collecting $5.7 billion in IEEPA duties on Mexican goods between Mar. 4 and Sep. 23, according to the most recent data available. Trump also has threatened to raise the IEEPA tariff on Mexico to 30 percent, but reportedly recently agreed to delay that move for several more weeks to allow time for talks.
Coping strategy: President Claudia Sheinbaum has stayed on Trump’s good side by declining to retaliate and working with the U.S. on fentanyl and illegal immigration concerns. She has kept that forbearance while Trump has piled new tariffs on Mexico’s exports of autos, auto parts and certain other products using Section 232.
Mexico’s ultimate goal is to maintain the preferential access it enjoys to the U.S. market under the USMCA, which is up for review next year, when countries have to say if they want to continue the pact past July 1, 2036, its current expiration date.
Sheinbaum told reporters on Oct. 27 that she hopes to resolve U.S. concerns over 54 Mexican non-tariff trade barriers in coming weeks.
While a return to tariff-free trade with the U.S. seems unlikely while Trump is in office, Mexico hopes to be treated better than most other trading partners, or at least no worse. That drama will play out in the first half of 2026.
By Doug Palmer
Doug Palmer and Phelim Kine reported from Washington, Camille Gijs from Brussels, Caroline Hug from London and Zi-Ann Lum from Ottawa.
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