US court blocks Trump tariffs, calling unchecked tariff authority ‘unconstitutional’
A US trade court has blocked sweeping ‘Liberation Day’ and fentanyl tariffs, determining that President Donald Trump had inappropriately used emergency powers to impose the tariffs.
On Thursday (AEST), the US Court of International Trade ordered the US administration to cease its 25 per cent fentanyl tariffs on Canada and Mexico, its 30 per cent fentanyl tariffs on China, and its 10 per cent global baseline tariffs.
The court determined that Trump’s use of emergency powers to impose tariffs at his own whim had been unauthorised under US law.
On multiple occasions, Trump has invoked the International Emergency Economic Powers Act of 1977 (“IEEPA”) to bypass Congress and impose tariffs as he saw fit. He has declared several “national emergencies” since taking office in January 2025.
The IEEPA says the president is permitted to “regulate … importation” to directly address an “unusual and extraordinary threat” to the US in the context of a national emergency.
On April 2, also known as ‘Liberation Day’, Trump invoked IEEPA powers to tariff almost every country in the world. To justify this decision, he declared that US trade deficits posed an “unusual and extraordinary” threat to the US, which constituted a national emergency.
On Thursday, the court found that the US trade deficit was not an adequate reason to justify the use of emergency powers.
“Even ‘large and serious United States balance-of-payments deficits’ do not necessitate the use of emergency powers,” court documents read.
Trump similarly used IEEPA powers to impose tariffs on Mexico, Canada and China, justifying them by declaring a “national emergency” due to the cross-border flow of fentanyl.
The court determined that the IEEPA provision did not authorise Trump to impose whatever tariff rate he deemed desirable.
“Indeed, such a reading would create an unconstitutional delegation of power,” court documents warned.
Furthermore, Trump’s fentanyl tariffs on Canada, Mexico and China did not directly deal with the fentanyl issue, and thus could not be justified within the scope of the emergency powers.
The court warned that the Trump administration’s interpretation of the emergency powers made them “trivially easy” to invoke.
“If ‘deal with’ can mean ‘impose a burden until someone else deals with,’ then everything is permitted,” the court said.
“It means a President may use IEEPA to take whatever actions he chooses simply by declaring them ‘pressure’ or ‘leverage’ tactics that will elicit a third party’s response to an unconnected ‘threat.’”
The Trump administration has hit back at the court’s decision, immediately filing a notice of appeal in response to its ruling against the tariffs.
In court filings, the Trump administration argued that the plaintiffs had improperly questioned his executive orders, “inviting judicial second-guessing of the president’s judgment.”
The court warned that an interpretation of IEEPA that would give the president full, unchecked authority over tariffs would be unconstitutional.
“These tools indicate that an unlimited delegation of tariff authority would constitute an improper abdication of legislative power to another branch of government,” court documents read.
“Any interpretation of IEEPA that delegates unlimited tariff authority is unconstitutional.”
