Trump’s tariffs are likely illegal

US President Donald Trump's sweeping tariffs on Mexican, Canadian, and Chinese imports rest on shaky legal ground.

- Aziz Huq

But they are unlikely to be struck down in court. By exploiting a gap between the law and brute power, the Trump administration is laying bare the weakness of America’s constitutional order.

The US Constitution assigns authority over foreign trade and taxation to Congress alone. While Mr Trump has made an extravagant show of ignoring Congress's duly enacted laws in recent weeks, his tariff orders themselves invoke federal law: the 1977 International Emergency Economic Powers Act (IEEPA). And yet, the IEEPA does not support Mr Trump's current tariffs.

The law’s language makes this clear. A president may declare a “national emergency” to address an “unusual or extraordinary” foreign threat to America’s “national security, foreign policy, or economy” Once that is done, the IEEPA grants vast emergency-specific powers, including the authority to “regulate” the “importation” of “any property” But these additional powers apply only to the emergency at hand; they may not be used for “any other purpose’,

Thus, in January, Mr Trump declared an emergency “at the southern border’, citing the threat posed by cartels, migration, and narcotics. Let us take this declaration at face value and assume that there is a crisis at the border. Even then, the tariffs imposed this month cannot plausibly be understood as a response to it.

This is most obvious with respect to Canada, a country that plays almost no role in supplying the American fentanyl market. The discontinuity between the vast tariffs being imposed on Canada and the notional emergency at the “southern border” is so glaring that the tariffs should be viewed as illegal on their face. The off-and-on nature of these tariffs underscores their lack of rational connection to any particular policy.