The U.S. Supreme Court recently heard arguments regarding former President Donald Trump’s tariffs on Canada and other allies. The case centers on the International Emergency Economic Powers Act (IEEPA), a 1977 law originally intended for imposing sanctions on adversaries like Iran and North Korea. The justices expressed skepticism about whether Congress intended to grant such broad taxing authority to the president. Trump’s legal team argued that the IEEPA allows the president to impose tariffs under the guise of “regulating importation.” This interpretation raises concerns that the term “regulate” could effectively mean “tax.” If accepted, this would enable the executive branch to impose tariffs without congressional approval, relying solely on a presidential proclamation. The Founding Fathers were clear about taxation without representation, assigning the power to tax to Congress. The justices questioned whether Congress could have casually surrendered this power through vague language. Chief Justice John Roberts directly asked the Solicitor General if the president could impose an income tax using the same rationale. The response was not definitive. Justice Sonia Sotomayor emphasized that taxation is a congressional power, while Justice Elena Kagan noted that Congress had removed revenue-raising verbs when it revised the IEEPA in 1977. Justice Brett Kavanaugh warned that the government’s interpretation could invert the IEEPA’s purpose, which was to limit emergency powers, not expand them. Even Justice Neil Gorsuch, typically supportive of executive authority, described the argument as a “remarkable claim of boundless power.” Following the hearing, constitutional and trade scholars raised concerns about Congress’s gradual relinquishment of fiscal authority over the years. This trend has allowed presidents to act in “emergencies” that seem to persist indefinitely. The potential ruling could formalize an arrangement that contradicts the Constitution’s intent, leading to taxation without representation under the guise of national security. For Canada, the implications are significant. The 25% tariffs imposed under these powers have severely impacted the Canadian economy. Companies like Algoma Steel and Stelco have reported substantial revenue losses, and production cuts have led to job losses. Bank of Canada Governor Tiff Macklem highlighted trade uncertainty as a major concern for Canada’s economic stability. Even if the Supreme Court rules against the IEEPA tariffs, Canada may still face ongoing trade challenges. The uncertainty surrounding U.S. trade policy could leave Canada vulnerable, as the relationship with the U.S. shifts from a rules-based framework to one dependent on the political climate in Washington. The Supreme Court’s decision will have lasting effects on American governance and the balance of power in North America. For the U.S., it will test the limits of presidential authority. For Canada, it raises questions about the reliability of its trading relationship with its largest partner. The outcome could redefine the nature of this partnership, shifting it from a collaborative agreement to one of dependence.