How Congress delegates its tariff powers to the president

President Donald Trump is expected to announce wide-sweeping tariffs on Wednesday, in a move with potentially broad consequences. So how does the president have the ability to levy tariffs under the Constitution?

The Constitution actually grants Congress the power to levy tariffs, but in recent years as a result of certain laws Congress has passed, the president and the executive branch have controlled when and how tariffs are placed on goods entering the United States.

The Constitution’s Article I, Section 8 states: “The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, … but all Duties, Imposts and Excises shall be uniform throughout the United States.”

Over time, as Congress gave the president expanded powers on its behalf to enact tariff policies, opponents to several tariffs laws argued the statutes were an unconstitutional congressional delegation of authority to the president. Known as the non-delegation doctrine, the question of how much of its authority Congress can grant to the president and the judiciary goes back to the time of Chief Justice John Marshall.

In Wayman v. Southard (1825), Marshall noted that Congress could not delegate powers “that are strictly and exclusively legislative.” But Congress had the ability to grant other powers as needed. “The difference between the departments undoubtedly is that the legislature makes, the executive executes, and the judiciary construes the law; but the maker of the law may commit something to the discretion of the other departments, and the precise boundary of this power is a subject of delicate and difficult inquiry, into which a court will not enter unnecessarily,” Marshall concluded.

The Court defined these boundaries regarding tariffs in a landmark decision from 1892, Field v. Clark. Marshall Field & Co. objected to tariffs placed on sugar, molasses, coffee, tea, and hides under the Tariff Act of 1890, which directed the president to place such levies when other nations used tariffs the president “may deem to be reciprocally unequal and unreasonable.” Marshall Field claimed Congress had improperly granted legislative powers to the president.

In his majority opinion, Justice John Marshall Harlan said the president was acting in his executive role executing a congressional policy. “What the president was required to do was simply in execution of the act of Congress. It was not the making of law. He was the mere agent of the lawmaking department to ascertain and declare the event upon which its expressed will was to take effect.”

Congress increasingly took a less active role in levying tariffs directly, especially after the 16th Amendment’s ratification in 1913 led to a federal income tax that replaced tariffs as a main source of federal government revenue. In 1934, Congress passed the Reciprocal Trade Agreements Act, which gave President Franklin Roosevelt the ability to change tariffs rates by 50% and negotiate bilateral trade agreements without additional approval from Congress. Since then, the president has mostly controlled and executed tariffs policies as defined by Congress.

Laws That Allow the President to Impose Tariffs

According to the Congressional Research Service, there are six statutory provisions currently in place that control how the president and the executive branch can use tariffs. Three provisions require federal agency investigations before a tariff can be imposed. The other provisions do not require an investigation before actions are taken.

Section 232 of the Trade Expansion Act of 1962 has been used by the first and second Trump administrations for steel and aluminum imports. It authorizes the president to ask the Secretary of Commerce to determine if goods are being imported in manner that threatens national security. The secretary then reports back to the president if he has any affirmative findings. “Section 232 does not require the President to follow the Secretary’s recommendations but permits him to take alternative actions or no action,” the CRS says. Under Section 232, there is no maximum time limit on the president’s tariff actions.

Another provision that requires an investigation is Section 201 of the Trade Act of 1974. The act allows the president to impose tariffs if the U.S. International Trade Commission (ITC) finds that an import surge is threatening a U.S. domestic industry. If the ITC makes an affirmative determination, the president can take action accordingly, including placing tariffs. Tariffs imposed under Section 201 are not meant to be permanent, and the actions have a limit of four to eight years.

Section 301 of the Trade Act of 1974 allows the United States Trade Representative (USTR) to authorize tariffs on foreign countries that restrict U.S. commerce in “unjustifiable,” “unreasonable,” or “discriminatory” ways. If the USTR confirms such behavior after an investigation, the president has the discretion to allow the USTR to impose tariffs for at least four years.

Among the three provisions that allow the president to act on his own to impose tariffs without an investigation, only one has ever been used: the International Emergency Economic Powers Act of 1977. The act allows the president to declare an emergency under the National Emergency Act (NEA) and then use his extensive economic powers to regulate or prohibit imports. The CRS says that President Trump was the first chief executive to use this act in February 2025, when he announced tariffs on Canada, China, and Mexico. The emergency stated by the president can be terminated at this request, or by a joint resolution of Congress.

Section 122 of the Trade Act of 1974, which allows the president to enact temporary tariffs to address “large and serious United States balance-of-payments deficits” or certain other situations that present "fundamental international payments problems;  and Section 338 of Tariff Act of 1930, which  authorizes the president to enact “tariffs on articles produced by, or imported on the vessels of, foreign countries that discriminate against U.S. commerce in certain ways,” have not yet been used.

Ultimately, Congress can limit or expand the presidential tariffs powers through legislation, but the CRS concludes that based on precedents dating back to the time of Chief Justice Marshall, judicial precedent “has given the President broad latitude to exercise his tariff authorities.”

Scott Bomboy is the editor in chief of the National Constitution Center.