In August 2026, President Trump slapped 50 per cent tariffs on around $20 billion of Canadian goods after trade talks between the two countries fell apart. Prime Minister Mark Carney branded the move a miscalculation, arguing the Americans had made demands no Canadian government could accept, and hit back with retaliatory tariffs on around 700 American products, matching the US dollar for dollar from 8 September. Trump responded in typical fashion, threatening to extend 50 per cent tariffs to Canadian cars, parts and steel in the new year, all while mocking Carney online as a mere state governor, a dig at his long-stated ambition to make Canada the fifty-first state.
Carney, who won office partly on a promise to stand up to Washington, is not backing down. He has been blunt that Canada will never be part of America in any way, shape or form. The provinces have raised the stakes further still. Ontario Premier Doug Ford, whose province keeps the lights on for 1.5 million American homes and businesses across Michigan, Minnesota and New York, has threatened to cut off electricity exports and critical minerals such as nickel and uranium if things escalate. What began as a spat between two leaders now involves sub-national governments with real leverage of their own.
The constitutional story here is the most revealing part. Trump originally imposed his Canadian tariffs through executive orders under the International Emergency Economic Powers Act. In February 2026 the Supreme Court ruled 6-3 that the statute gives the president no such power, with Chief Justice Roberts pointing out that the Constitution hands the power to tax and impose duties to Congress alone. Trump was forced to scrap those orders and reach instead for Section 338 of the Tariff Act of 1930, a dusty provision no president had ever used, and one lawyers fully expect to end up in court as well. Executive orders are fast, but they are also fragile.
So what does this tell us about presidential power? Both sides of the debate find ammunition here. Trump acting unilaterally, without Congress, on a matter of huge economic consequence looks like the imperial presidency in action. Yet the courts struck his flagship tariffs down entirely, and a foreign leader simply refused to fold. Presidential power is not fixed but contested, checked by judges at home and stubborn opponents abroad, and always resting on laws that Congress could take back.