Donald Trump's global tariff war isn't just provoking backlash abroad — it's now facing its toughest battle at home.

On Wednesday, the US Supreme Court heard arguments challenging Trump's sweeping use of "emergency powers" to impose tariffs on imports. A majority, including Trump's own appointees, openly questioned his authority to slap taxes on goods without Congress. This follows three lower courts ruling his actions illegal. Reflecting the skepticism, the prediction platform Polymarket has slashed Trump's odds of winning from 40% to about 30%.

A final ruling may take months, but the effect is already harsh: volatile tariff policy has disrupted imports, driven inflation higher, and squeezed small businesses and households alike. Trump said tariffs are "beautiful", but for ordinary Americans, they've been anything but.