The blockbuster Supreme Court tariffs case poses a crucial question about presidential power

What to know about the case that could rein in Trump’s sweeping concept of presidential power — or endorse it.

Donald Trump during a “Make America Wealthy Again” trade announcement at the White House on April 2, 2025.Chip Somodevilla / Getty Images
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As Americans wake up on Wednesday morning to election results that, in some places, decide who will run our cities and states, the justices of the Supreme Court will just be getting started on a case that could carry just as many consequences, but for our highest elected official: the president.

In what will be one of the most closely watched cases this term, the court will hear oral argument about whether a president may impose wide-ranging tariffs under the International Emergency Economic Powers Act. Further, it will consider whether President Donald Trump is entitled to rely on IEEPA in imposing both “reciprocal” tariffs on almost all other countries and fentanyl-related tariffs on Canada, Mexico and China.

What is the IEEPA, and how is President Trump using it to impose tariffs?

IEEPA, enacted in 1977, gives the president the authority to respond to any “unusual and extraordinary threat ... to the national security, foreign policy, or economy of the United States” if he declares a national emergency concerning that threat. And once he declares such an emergency, the president can investigate, regulate or prohibit, among other things, any imports or exports.

In defending Trump’s tariffs before the Supreme Court, the Justice Department has pointed to several Trump executive orders declaring national emergencies.

One of those orders centered on goods trade deficits, which Trump has said hampered the production of goods domestically and compromised national security and military readiness. In declaring it a national emergency, Trump also ordered reciprocal tariffs: a 10% universal tariff and additional, country-specific tariffs ranging from 11% to 50%.

Other orders framed the distribution of fentanyl as another national emergency and found that the failure of China, Canada and Mexico each to stem the flow of fentanyl into the U.S. constituted the kind of “unusual and extraordinary threats” that justify a 25% “trafficking” tariff on most Mexican and Canadian goods, as well as a 10% duty on most Chinese imports.

What are the arguments before the court?

The core statutory question before the Supreme Court is whether the president has the power to “regulate” tariffs. Opponents of Trump’s tariff actions characterize them as a tax that only Congress can impose; the administration, on the other hand, insists that taxes are a form of regulation — and it can rely on some founding-era writings, as well as an early Supreme Court opinion, to frame tariffs as regulation, not taxes or duties.

But there’s more: If the court finds that the IEEPA does give Trump broad tariff authority, it will also need to determine whether the act itself is unconstitutional in giving the president, rather than Congress, the power to wield it.

Who is challenging the tariffs, and how did the case get to the Supreme Court?

The tariff case was originally two cases brought by two distinct groups of plaintiffs: a handful of small businesses that allege their very survival is threatened by Trump’s tariffs, and a coalition of states, led by Oregon, that not only import goods but purchase imported goods as well.

Among the small businesses are a New York-based wine and liquor importer and distributor; asked how he experienced “Liberation Day,” on which Trump announced the tariffs, the owner of that business, Victor Schwartz, told MSNBC this week that he refers to it as “strangulation day.”

The other small businesses include two Illinois-based educational toy and game companies owned by the same family for four generations. Their products are developed in the U.S. but manufactured abroad.

The two cases — which the Supreme Court consolidated into one — first arrived from lower federal courts on the high court’s “shadow docket,” through which it considers emergency applications. It has since moved to the court’s “merits docket,” through which the justices will hear oral argument before making a decision.

What will happen on Wednesday, and who are the justices to watch?

The stakes are high, not only for Trump’s economic agenda but also for his vision of presidential power, but don’t expect to have any answers right away, as a decision could be weeks or even months down the road. The Supreme Court often reserves decisions on its most consequential cases for the last weeks of June, which mark the end of its term.

When it comes to how the Supreme Court will rule, there is a fundamental element underlying many decisions: The justices themselves and who each was personally and professionally before they became one of “the nine.” It’s worth asking how their formative experiences shaped their understanding not only of the separation of powers, but also of the relative balance of powers among the three branches of government.

The answers are particularly revealing — and could come into play in the tariffs case — when it comes to Trump’s three nominees to the Supreme Court: Justices Neil Gorsuch, Amy Coney Barrett and Brett Kavanaugh.

On one hand, both Gorsuch’s and Barrett’s histories suggest the Trump tariff roller coaster could screech to a halt.

Gorsuch has been unusually critical of — and eager to curtail — what he sees as executive overreach, whether through regulation gone amok or Congress’s willingness to delegate its own reserved powers to the executive branch.

Justice Barrett spent 15 years as a legal academic while parenting seven children; as one might expect from a professor, her jurisprudence is both precise and pragmatic, with a hint of maverick. Consider where Barrett fell in a 2024 case that by a 6-3 majority narrowed the meaning of a federal statute used in many Jan. 6 prosecutions. Barrett, joined by liberal Justices Sonia Sotomayor and Elena Kagan, dissented, reminding the majority that the Supreme Court “ordinarily resist[s] reading words or elements into a statute that do not appear on its face,” an approach that could bode well for tariff opponents.

But Barrett’s insistence on plain meaning could be met in the tariffs case by an equally powerful force: Justice Brett Kavanaugh. His résumé pre-Supreme Court includes a long stint at the White House during George W. Bush’s tenure, when, as staff secretary, he not only determined which documents warranted the president’s review but also solicited input from relevant stakeholders within the White House and executive branch on key decisions, then made sure staff executed them.

Given that, it’s hardly coincidental that Kavanaugh has become one of the court’s most reliable defenders of expansive presidential power. In fact, Kavanaugh foreshadowed his belief in an unencumbered president in a 2009 law review piece in which, recalling his White House tenure, he said it was “vital that the President be able to focus on his never-ending tasks with as few distractions as possible.”

The question, of course, is whether Trump’s tariffs properly fit within those “never-ending tasks” on the president’s to-do list or instead are the province of Congress. Eighty minutes on Wednesday — the scheduled duration of the oral argument — may provide the first clues to that answer.

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