The case that could rewrite American power — and Canada's trade reality 

The U.S. Supreme Court heard arguments last Wednesday over Donald Trump’s “emergency” tariffs on Canada and other allies. What unfolded wasn’t simply another trade dispute. The justices revealed deep skepticism about whether Congress ever intended to surrender its taxing power so broadly to any president.

At stake: the International Emergency Economic Powers Act, a 1977 statute designed for sanctions against adversaries like Iran and North Korea. Nobody imagined it would become a weapon against Canada.

Trump’s lawyers made an audacious argument. They claimed IEEPA allows the president to impose tariffs under the banner of “regulating importation.” As a U.S. law professor who teaches U.S. law, I can tell you what that means in practice: the word “regulate” becomes “tax.” If they’re right,