On October 1, 1890, President Benjamin Harrison signed a tariff bill named for its sponsor, Representative William McKinley of Ohio. It put sugar, molasses, coffee, tea and hides on the free list. Then it added a catch. If a country exporting those goods taxed American products in a way the president judged “reciprocally unequal and unreasonable,” he could suspend their free entry by proclamation. Duties that Congress had already written into the law would then apply.
A Chicago firm, Marshall Field & Co., argued that this gave the president a power the Constitution reserves to Congress. The Supreme Court disagreed. That 1892 ruling is the first link in a chain that runs to the tariffs in the news today.
This post answers one question: when a president raises tariffs, whose power is he using, and what has the Supreme Court said about its limits? It explains the cases, up to the Court's February 2026 ruling on the tariffs imposed under IEEPA.
The power starts with Congress
The Constitution is unusually direct here. Article I, Section 8 gives Congress the power “To lay and collect Taxes, Duties, Imposts and Excises” and “To regulate Commerce with foreign Nations.” A tariff is a duty on imports, so it falls within Congress's list. Article II gives the president no tariff power of his own.
For most of the nineteenth century, Congress set rates itself, item by item, in long bills that took months to pass. The trouble was practical. Rates fixed in a statute go stale as prices and foreign policies change, and Congress cannot rewrite the tariff schedule every time another country changes its own. So Congress began letting the president adjust. That raised a legal problem. The Court has long said Congress cannot give away its legislative power. Lawyers call this principle the nondelegation doctrine, and every tariff case in this story is, at bottom, about where its line falls.
1892: The president as fact-finder
In Field v. Clark (1892), decided 8-0, the Court upheld the McKinley Tariff's reciprocity section. Its reasoning shaped everything that followed. The Court said Congress had not let the president make law. Congress had made the law, duties included, and had told the president to watch for one thing: whether another country treated American goods unequally and unreasonably. Once he found that fact, the policy Congress had already chosen took effect. In the Court's framing, the president acted as Congress's agent in deciding when the condition was met, not as a lawmaker. Justice Lucius Q.C. Lamar, joined by Chief Justice Melville Fuller, agreed with the result but wrote separately to reject that reasoning: in their view, the reciprocity section did delegate legislative power to the president.
The case is also known for a second holding, often called the enrolled bill rule. Courts treat a bill signed by the presiding officers of Congress and by the president as the law Congress actually passed, and they will not dig through legislative journals to second-guess it.
1928: The intelligible principle
The next step came with the Tariff Act of 1922. Its “flexible tariff” provision let the president raise or lower a duty by up to 50 percent to equalize the cost of producing a good in the United States and abroad, after an investigation by the Tariff Commission. President Calvin Coolidge used it to raise the duty on barium dioxide, an industrial chemical, from 4 to 6 cents a pound. An importer, J.W. Hampton, Jr. & Co., paid the higher rate under protest and sued.
In J.W. Hampton, Jr. & Co. v. United States (1928), the Court ruled 9-0 for the government. Chief Justice William Howard Taft, himself a former president, wrote the opinion. Congress may enlist the other branches, he reasoned, as long as it lays down an “intelligible principle” that whoever exercises the power must follow. Equalizing production costs qualified.
That phrase did a great deal of work. It became the general test for delegations of every kind, not only tariffs, and it proved easy to meet. The Court has struck down federal statutes as unconstitutional delegations only twice, both in 1935 and both involving New Deal programs: Panama Refining Co. v. Ryan (1935) and A.L.A. Schechter Poultry Corp. v. United States (1935). Neither was a tariff case.
Congress kept delegating. The Reciprocal Trade Agreements Act of 1934 let the president negotiate trade deals that cut tariffs by up to half without a new vote on each one. Two years later, in United States v. Curtiss-Wright Export Corp. (1936), the Court upheld a law letting the president ban arms sales to Bolivia and Paraguay, then at war, and wrote broadly about the president's role in foreign affairs. That opinion is still cited whenever a president's power abroad is tested.
National security and emergencies
After World War II, delegations shifted from rate-setting toward national security. Section 232 of the Trade Expansion Act of 1962 lets the president “adjust” imports of an article if the Commerce Department finds those imports threaten to impair national security. The Trade Act of 1974 added other tools, including Section 301, aimed at unfair foreign trade practices, and Section 122, which allows temporary duties to address balance-of-payments problems.
In 1975 President Gerald Ford used Section 232 to impose license fees on imported oil. Several states and utilities sued, arguing the statute allowed quotas but not fees. In Federal Energy Administration v. Algonquin SNG, Inc. (1976), the Court ruled 9-0 that “adjust” was broad enough to include fees. It also held that the statute's standards, a national security finding plus factors the president must consider, easily passed the intelligible-principle test. When importers challenged the 2018 steel and aluminum tariffs under Section 232, lower courts said Algonquin bound them. In American Institute for International Steel v. United States (2020), the Court of International Trade rejected the nondelegation challenge in March 2019, with Judge Gary Katzmann agreeing that Algonquin controlled while doubting the statute would survive without it. The Federal Circuit affirmed in February 2020, and the Supreme Court declined to hear the case on June 22, 2020.
A second line runs through emergency law. In 1971 President Richard Nixon imposed a 10 percent surcharge on most imports, relying on the Trading with the Enemy Act of 1917. A federal appeals court upheld it in United States v. Yoshida International (1975), reading the act's power to regulate importation to cover the surcharge, while noting the measure was temporary and limited.
In 1977 Congress narrowed that wartime statute and passed the International Emergency Economic Powers Act, known as IEEPA. Once the president declares a national emergency to deal with an “unusual and extraordinary threat” originating in whole or in substantial part outside the United States, IEEPA lets him regulate or prohibit a range of transactions involving foreign property, including importation. The word “tariff” does not appear in it. Whether the power to regulate importation includes the power to impose tariffs became the main statutory question in the challenges to the 2025 tariffs.
How far the president's own power reaches
The delegation cases ask what Congress gave. Two other cases ask how courts should judge a president's claim of authority in the first place.
In Youngstown Sheet & Tube Co. v. Sawyer (1952), President Harry Truman seized the nation's steel mills to head off a strike during the Korean War. The Court ruled 6-3 that he lacked the power. Justice Hugo Black's majority opinion said the seizure order was lawmaking, which belongs to Congress. Justice Robert Jackson's concurrence has proved more influential. He sorted presidential action into three groups. When the president acts with Congress's authorization, his power is at its height. When Congress has said nothing, he works in a “zone of twilight.” When he acts against Congress's will, his power is “at its lowest ebb.” Tariff disputes usually turn on the first group, because the president almost always points to a statute. The fight is over whether the statute actually covers what he did.
Dames & Moore v. Regan (1981) applied Jackson's framework. To end the Iran hostage crisis, President Jimmy Carter agreed to cancel court orders freezing Iranian assets and to send claims against Iran to an international tribunal. The Court, ruling 8-1, held that IEEPA authorized cancelling the asset orders. For the suspension of claims, it found no direct statutory authority but relied on Congress's long acceptance of similar settlements. Justice William Rehnquist's opinion stressed that the decision was narrow. The case gets cited both ways: as proof that IEEPA's powers are broad, and as a reminder that the Court checked closely what Congress had actually approved.
Two ways to read the same cases
The case for broad presidential authority. On this reading, the statutes mean what they say. Congress chose expansive words such as “adjust” and “regulate” and tied them to national security and emergencies, areas where courts have traditionally deferred to the president. Algonquin read “adjust” broadly. Yoshida read the power to regulate importation to cover a surcharge. Curtiss-Wright and Dames & Moore emphasize the president's role in foreign affairs. If Congress dislikes how the power is used, it can amend the laws.
The case for limits. On this reading, the history shows how far delegation has drifted from Field v. Clark, where Congress set the duties itself and the president only found a fact. A statute read to let the president set any rate on any country during any declared emergency, critics argue, has no real intelligible principle, so courts should not read it that way. They point to the major questions doctrine, under which courts expect Congress to speak clearly before the executive branch exercises power of vast economic and political significance, and to the Constitution's decision to place the taxing power in Congress.
Both sides rely on the same precedents. They disagree mainly about which features of those precedents matter.
What's changed since the older cases
Several decisions since 2019 make the older precedents look less settled. In Gundy v. United States (2019), the Court rejected a nondelegation challenge, but Justice Neil Gorsuch, joined by Chief Justice John Roberts and Justice Clarence Thomas, dissented and called for a stricter test. Justice Samuel Alito wrote that he would support reconsidering the approach with a full Court. Justice Brett Kavanaugh, who did not take part in Gundy, later wrote in another case that the question may deserve further consideration. In June 2025, though, the Court rejected another nondelegation challenge in FCC v. Consumers' Research (2025), applying the intelligible-principle test.
In West Virginia v. EPA (2022), the Court formally named the major questions doctrine, and in Biden v. Nebraska (2023) it applied the doctrine to student loan forgiveness. Those cases involved agencies. Whether the doctrine applies the same way to powers given directly to the president, especially in foreign affairs, is disputed. In Loper Bright Enterprises v. Raimondo (2024), the Court overruled the Chevron doctrine, which had told courts to defer to reasonable agency readings of unclear statutes. Courts now decide for themselves what words like “regulate importation” mean.
Then came the current tariffs. In 2025 the administration imposed new tariffs under several statutes. On February 1 it used IEEPA to impose tariffs on goods from Canada, Mexico and China, tied to drug trafficking and migration, and on April 2 it used IEEPA again for worldwide "reciprocal" tariffs. Under Section 232, it expanded the steel and aluminum tariffs by proclamations on February 10 and added tariffs on automobiles on March 26. Challenges to the IEEPA tariffs reached the Supreme Court in Learning Resources, Inc. v. Trump (2026) and Trump v. V.O.S. Selections, Inc. (2026), brought by importers against the president. The Court heard argument on November 5, 2025, and on February 20, 2026, it ruled 6-3, in an opinion by Chief Justice Roberts, that IEEPA does not authorize the president to impose tariffs. Tariffs are also a political issue ahead of the November 2026 midterm elections, and a Chatham House analysis published on October 22 discusses voters' anger over tariffs and argues the midterms are unlikely to bring quick change.
Why the history matters now
Every delegation in this story made sense when Congress passed it. Lawmakers wanted tariffs that could respond faster than a legislature can, and they wanted the president to have tools in a crisis. Read alone, each grant looked modest. Read together, they moved the practical power to set tariffs from the Capitol to the White House, without Congress ever voting to give up its Article I role. The question for the courts was never whether that drift was wise. It is narrower: what the specific words Congress wrote actually authorize, and how much the Constitution lets Congress hand over. In February 2026 the Court answered that question for IEEPA, holding that its power to regulate importation does not include the power to impose tariffs. The ruling concerned that one statute. The larger question, whether Congress's oldest powers can be given away a statute at a time, and what it takes to get them back, is the one this history leaves open.
Sources
- Field v. Clark, 143 U.S. 649 (1892), Justia
- J.W. Hampton, Jr. & Co. v. United States, 276 U.S. 394 (1928), Justia
- Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579 (1952), Justia
- Federal Energy Administration v. Algonquin SNG, Inc., 426 U.S. 548 (1976), Justia
- Dames & Moore v. Regan, 453 U.S. 654 (1981), Justia
- Heather Hurlburt, "US voters are angry. But on tariffs and war, the midterms won't bring quick change," Chatham House (October 22, 2026)
