The Power of Tariffs: Has the US President Gone Too Far?
A point that may have been lost on non-US audiences watching in bewilderment at the US president’s tariff decisions is the constitutional basis of trade policy in the United States. Under the US Constitution, trade policy is not a power of the President. It is rather a power of Congress, responsible for regulating 'Commerce with foreign Nations, and among the several States, and with the Indian Tribes'. So, why then does the president seem able to do whatever he wants in this space? And, given the unprecedented scope of the duties that have been imposed in recent weeks: has the US president gone too far?
A history of Congress delegating powers to the President
Over the decades, Congress has delegated much of its authority to impose tariffs to the executive. Several statutes do this, with the best known being sections 232 of the Trade Expansion Act of 1962 and section 301 of the Trade Act of 1974.
Section 232 allows the President to impose tariffs based on national security concerns, such as importing steel and aluminium. President Trump already used this authority in his first term when he imposed duties of 10% and 25% respectively on certain imports of aluminium and steel. And he did so again on February 10, 2025, when he imposed tariffs on steel, aluminium, and on March 26, 2025 when he did the same on cars.
Section 301 of the Trade Act of 1974 lets the US Trade Representative, the US federal government agency responsible for trade policy, act against countries that violate trade agreements or engage in unfair trade practices, like intellectual property theft. During the first Trump administration, the US Trade Representative used this authority to target Chinese imports in 2018. The Biden administration increased the duties in 2024 following a mandatory review.
Another delegation that has recently been central to the US president’s decisions is the International Emergency Economic Powers Act (IEEPA). This act allows the President to regulate international commerce after declaring a national emergency due to an unusual and extraordinary threat to the US from abroad. Under IEEPA, the President can block transactions, freeze assets, and confiscate property connected with a country, group, or person that aided in an attack on the US. The President must declare a national emergency via executive order.
For example, President Obama adopted an executive order on March 16, 2014, the day Russian forces occupied Crimea. This is the authority the current US president used to impose tariffs on Mexico and Canada earlier this year. Hence, the talk of a fentanyl crisis, even though hardly any fentanyl flows from Canada into the US. A national emergency had to be found (or fabricated) for using IEEPA.
Has the US president gone too far?
IEEPA was not used to impose tariffs until recently. Now it is. This raises the question: has the US president gone too far? And if he has, what can be done about it? To answer that, we need to look at two players: Congress and the courts.
Congress delegated the powers initially. What was given can be taken away. Congress could revoke some (or all) of the delegations to the President. It could also revoke an individual emergency declaration, thereby clipping the president's wings on a specific file. However, the President holds a veto. He can block Congress from acting. Congress can override the veto, but this needs a two-thirds majority in both houses, meaning about half of the Republican caucus would need to stand against Trump. This is not likely now, but it could happen. The damage Trump is wreaking might make his coalition crumble. There are in fact sings that this is starting to happen. On April 3, 2025, four Republicans joined Democrats in a Senate vote to rescind the president’s Canada tariffs.
The second player is the federal courts. A federal court could rule the president overstepped his authority, for example, by declaring a fabricated fentanyl crisis a national emergency, or, as the governor of California has now asked a federal court to rule: by declaring that the US president lacks the authority to impose tariffs on the basis of the abovementioned IEEPA.
Or, as argued also by Georgetown Law professor Jennifer Hillman on the Lawfare blog (and mentioned in the California governor’s petition): perhaps a recently emerged constitutional doctrine that bars the executive from tackling ‘major questions’ through executive action alone also bars the US president from relying on IEEPA to impose tariffs as sweeping as those imposed in recent weeks. This latter argument is particularly interesting, considering that the Supreme Court has relied on this doctrine to strike down president Biden’s student debt cancellation programme. If cancelling student debt is a major question that requires legislative action, arguably imposing sweeping tariffs that have wiped out trillions of stock value and threaten thousands of jobs is a major question as well.
As I have described elsewhere, US federal courts have been deferential to the president, but that might change. The current Supreme Court has shown a willingness to overturn previous decisions, as evidenced most spectacularly by its reversal of Roe v. Wade in the context of abortion rights in the US.
In conclusion, the president has significant power to impose tariffs, but these are delegated and limited powers. Recent actions have ignored these limits. The developments in Congress and federal courts will be interesting to watch.
