President Trump raised tariffs on all US imports to 15% in the immediate aftermath of the Supreme Court’s ruling that his previous tariff authority was unconstitutional. The new tariffs are based on Section 122 of the Trade Act of 1974 — a provision never previously used — and are limited to 150 days before requiring congressional approval. Trump described the measure as “fully allowed and legally tested” and vowed to develop new, legally durable tariff mechanisms during the 150-day window.
The Supreme Court ruled 6-3 that Trump had exceeded his authority under the International Emergency Economic Powers Act (IEEPA) in imposing the original sweeping tariffs. The ruling found that tariffs of this breadth require congressional authorization — a significant constitutional statement that two of Trump’s own nominees joined. Trump responded furiously, calling the majority justices “unpatriotic” and a “disgrace,” and praised the three dissenters: Kavanaugh, Thomas, and Alito.
Key exemptions from the new 15% tariff include critical minerals, metals, pharmaceuticals, and USMCA-compliant goods from Canada and Mexico. Sector-specific tariffs on steel, aluminum, lumber, and autos imposed under different legal authority remain in place and were unaffected by the Supreme Court ruling. The US has collected over $130 billion in IEEPA tariffs, with studies showing that 90% of those costs were borne by American businesses and consumers.
International reactions were swift. German Chancellor Merz called tariff uncertainty “poison” for transatlantic economies and announced plans to bring a coordinated European position to Washington. French President Macron praised the Supreme Court ruling as a model of democratic governance and called for reciprocity in trade. The UK, which had a 10% tariff arrangement with the US, found that deal effectively superseded by the new 15% rate. Business groups across the Atlantic called for stability and warned of the damage to global trade and economic growth.
The 150-day window the new tariff provides will be a critical period for US trade policy. The administration will seek to develop new tariff mechanisms; Congress will face pressure to assert its constitutional role; courts are widely expected to challenge the new authority; and international trading partners will recalibrate their strategies. For American consumers and businesses bearing 90% of tariff costs, the outcome of that 150-day period could not be more consequential.