Explaining the Trump Tariff Legal Cases

Demystifying some of the complex constitutional and statutory interpretation issues surrounding the legality of Trump's tariffs.

On May 28, 2025, a three judge panel of the United States Court of International Trade (the “Court of International Trade”) held that Trump’s tariffs were illegal. Before those who don’t want the economy to collapse could celebrate though, the United States Court of Appeals for the Federal Circuit then stayed the decision the next day, leaving Trump’s tariffs in place.

That same day, a United States District Court for the District of Columbia (the “D.C. District Court”) then struck down Trump-imposed tariffs as illegal. However, the tariffs remain in effect as the judge stayed his own decision for fourteen (14) days.

The legal situation is confusing to most.¹ It’s also extremely frustrating for many Americans who witness the devastating economic effects of Trump’s tariffs (as

Noah Smith

recently tweeted, “Tariffs are screwing American manufacturing”²) and would be relieved to know they were illegal.

Generally, there has been non-stop whiplash on tariffs where Trump threatens a tariff and then decides to not implement it or delays it at the very last minute. Frankly, I cannot keep up with the daily changes on which Trump tariffs have been put into effect and which ones have not.

Last month, after proposing massive tariffs on foreign produced films (that would be disastrous for Hollywood), in Trump Finds His Class War Wedge Issue in Hollywood: Movie Tariffs, journalist

Peter Kiefer

wrote of the proposed movie tariffs: “It’s unclear how it would work. No one knows what it would cost. And it’s anyone’s guess whether it will ever actually happen.”

That really sums up living under the Trump Administration.

The new legal battles over tariffs likely only add more confusion to the mix. As

Steve Vladeck

pointed out in What District Court Critics Aren't Telling You, many of Trump’s legally challenged executive orders are not lawful.

However, the reporting on Trump’s trade wars has operated on the assumption that Trump has the legal authority to unilaterally impose tariffs. The decisions from the Court of International Trade and the D.C. District Court have up-ended that assumption.

Even though they both agreed on the larger issue that the tariffs were illegal, the courts arrived at two very different legal conclusions.

• The Court of International Trade ruled that Trump does not have the authority to implement some of his tariffs under the International Emergency Economic Powers Act of 1977 (the “IEEPA”) and exceeded his authority under the IEEPA to impose some of his other tariffs because those tariffs fail to relate to a declared national emergency.

• The D.C. District Court ruled that the IEEPA does not give Trump any authority to impose tariffs at all. The Court ruled this way in order to actually hear the case.

Both courts further reasoned that if they agreed with Trump’s interpretation of the IEEPA, the IEEPA would be unconstitutional. They applied a theory of law known as the major questions doctrine where, when possible, courts will interpret laws in a way to avoid striking them down as unconstitutional.³

If you’re confused, don’t feel bad. You’re not alone.

But while I struggle to follow the daily twists and turns of Trump Administration drama regarding the imposition of tariffs, this article will attempt to demystify the legal issues around Trump’s tariffs.

It may be helpful to start from the beginning.

Under the United States Constitution, Congress has the authority to set tariffs as one of its legislative powers.⁴ The President has no unilateral constitutional authority to enact tariffs.⁵ Congress cannot give away its legislative powers to other branches.⁶ However, while Congress cannot completely give away its legislative powers, it can delegate some of its legislative powers.⁷

Because of the complex reality of the modern world, there is some leeway for Congress to enact laws that give discretion to the President.⁸ Congress cannot legislate for every situation that can arise.⁹ Therefore, Congress can properly delegate its constitutional authority when it has laid down limiting principles and guidelines to guide the executive agency.¹⁰

Thus, Congress has delegated some of its authority to the President to set tariffs. The courts have upheld these laws as permissible delegations of Congressional authority.¹¹

This includes the Trading with the Enemy Act, which Congress originally enacted in 1917. After President Richard Nixon used it to impose additional tariffs in 1971, Congress subsequently amended the law in 1977 to only allow the President to set different tariffs during times of actual war.

Trump is not claiming that the United States is at war (we’re not - the United States hasn’t been in a declared state of war since World War II ended). Instead, he is claiming that the IEEPA gives him the authority to enact his sweeping tariffs.

As noted by both the Court of International Trade and the D.C. District Court, no President has ever invoked the IEEPA before to impose a tariff increase.

What is the IEEPA exactly?

The IEEPA allows the President to “to deal with any unusual and extraordinary threat, which has its source in whole or substantial part outside the United States, to the national security, foreign policy, or economy of the United States” if the President declares a national emergency “with respect to such threat.”¹²

The national emergency that the President invokes must be one that falls under the National Emergencies Act.¹³ Otherwise, the President cannot use the IEEPA to govern.¹⁴ Trump has argued that the IEEPA has given him the authority to impose his tariffs.

The IEEPA specifically provides that under certain conditions, the President may:

[I]nvestigate, block during the pendency of an investigation, regulate, direct and compel, nullify, void, prevent or prohibit, any acquisition, holding, withholding, use, transfer, withdrawal, transportation, importation or exportation of, or dealing in, or exercising any right, power, or privilege with respect to, or transactions involving, any property in which any foreign country or a national thereof has any interest by any person, or with respect to any property, subject to the jurisdiction of the United States.¹⁵

Here’s where the courts diverged on their reasoning to hear the case.

Federal law provides that legal trade disputes can only be heard in the Court of International Trade.¹⁶ Federal law also provides that such trade disputes cannot be heard in other federal district courts, which includes the D.C. District Court.¹⁷

The Court of International Trade held that the challenge to Trump’s tariffs could only be heard in its court.

The D.C. District Court disagreed, holding that since the IEEPA did not authorize Trump to impose tariffs but only the power to regulate imports and exports for national emergencies, the dispute did not arise out of a tariff case. The Court explained that “To regulate is to establish rules governing conduct; to tariff is to raise revenue through taxes on imports or exports.”

There is legal precedent that the power to regulate is separate from the power to tax.¹⁸ The IEEPA allows the President to regulate both importation and exportation of goods.¹⁹ Yet the Constitution prohibits tariffs and taxes placed on exports.²⁰

Nevertheless, I am honestly a tad skeptical of the D.C. District Court’s reasoning on their authority to hear the case. It seems that the case clearly does arise from the implementation of tariffs even if the IEEPA does not legally authorize Trump to impose tariffs.

By analogy, imagine the law says that I can only bring civil cases for dog theft and animal cruelty in the Court of International Trade and that no other court, including the D.C. District Court, can hear the case.

Cruella DeVille kidnaps my dog and abuses him. After he escapes her bumbling henchmen, I bring a lawsuit against Cruella DeVille for stealing my dog and subjecting him to animal cruelty. But I file my lawsuit in the D.C. District Court instead of the Court of International Trade.

Cruella DeVille claims, as a defense to my lawsuit, that the Violence Against Women Act gives her the right to steal and abuse my dog.

The D.C. District Court agrees to hear my case against Cruella DeVille because it reasons that the case arises from the Violence Against Women Act.

Granted, the Violence Against Women Act doesn’t give her that right. But that’s beside the point. The case really doesn’t arise out of the Violence Against Women Act. It arises out of Cruella DeVille kidnapping and abusing my dog.

Let’s say, Cruella DeVille appeals the D.C. District Court’s ruling allowing me to bring my case against her and the United States Circuit Court of Appeals for the District of Columbia reverses the lower court on the grounds that it lacked authority to hear my case.

The news media and political punditry are likely to report the outcome as the courts affirming Cruella DeVille’s right to kidnap and abuse my dog under the Violence Against Women Act. That shorthand reporting though is inaccurate and would confuse the public. It’s not that Cruella DeVille has that right, it’s that I brought my case in the wrong court.

Similarly, if the D.C. District Court’s decision to hear the case is overturned on appeal, it doesn’t mean that the IEEPA gives Trump unilateral authority to impose his tariffs. It will simply mean that the D.C. District Court was the wrong court for the parties to file in.

Indeed, the Court of International Trade felt differently than the D.C. District Court, ruling that their Court had exclusive authority to hear the case.

However, the Court of International Trade agreed with the D.C. District Court that the Worldwide Tariffs and Retaliatory Tariffs were illegal, holding that the IEEPA did not give the President authority to set unbounded tariffs as he pleased, as doing so would violate the constitutional separation of powers between the branches.²¹

The Court of International Trade further held that the Trafficking Tariffs were illegal because they failed to meet any of the four requirements under the IEEPA for enactment under an emergency:

1. There must be a “threat . . . which has its source in whole or substantial part outside the United States, to the national security, foreign policy, or economy of

2. The threat must be “unusual and extraordinary”.

3. A national emergency must be declared with respect to the threat.

4. The President’s exercise of IEEPA authority must deal with the threat.

The Court of International Trade reasoned, there was no declared national emergency, there was no unusual and extraordinary threat, and the President’s tariffs did not address any of the problems of identified as part of his claimed emergency threat.

What is the likely outcome of these cases on appeal? It’s unclear.

Trump is the first President to ever invoke the IEEPA to implement tariffs. Thus, the issue has never been litigated before and the case is one of first impression. It seems from reading the IEEPA that Trump has no legal authority to implement these tariffs. But without a firm legal precedent, it’s not easy to predict how appellate courts will rule on the matter.

If the higher courts are consistent, they will likely affirm at least the Court of International Trade’s decision against Trump’s tariffs. That’s because of late, the Supreme Court has been restricting Congressional power to rein in the President’s authority to hire and fire executive agency heads on the grounds that this impermissibly intrudes into executive powers granted by the Constitution.²²

Surely, it would be anomalous to allow the President to run roughshod over legislative powers expressly granted to Congress by the Constitution while also strictly interpreting the Constitution to not allow Congress to run roughshod over executive powers granted to the President.

Of course, some conservative judges and Supreme Court Justices are never shy about taking completely inconsistent positions in order to achieve the political result of their choice.

However, the Courts have not greenlighted everything Trump has done, sometimes consistently sticking to established principles and precedents. There is every possibility that these tariff rulings, particularly the Court of International Trade’s decision, will be affirmed.

In the words of Rachel Maddow, “watch this space.”

1. The author of this article is an attorney licensed to practice in the State of California and the District of Columbia. This article and all of the works on this Substack page are statements of the opinions of the author, only, and do not constitute legal advice; they are not intended to be relied upon by any individual or entity in any transaction or other legal matter, past, pending, or future. A paid subscription to this Substack page supports the author’s scholarship and provides access to research that the author has compiled, but does not establish an attorney-client relationship. The author does not accept unsolicited requests for legal advice or representation, and this Substack page is not intended as legal advertising. The opinions expressed on this Substack page reflect the personal views of the author only.

2. https://x.com/Noahpinion/status/1929717357750243695