Supreme Court Deems Some Trump Tariffs Illegal; Cars and Car Part Duties Remain

• The Supreme Court of the United States ruled that Trump's tariffs under the International Emergency Economic Powers Act are illegal. 
• The ruling does not affect the tariffs on autos or raw materials like steel and copper. 
• Prices on cars might not change for a while. 

The Supreme Court of the United States today deemed some of President Donald Trump's tariffs illegal because he did not seek or obtain congressional approval. The 6-3 decision stopped short of saying what will happen to the $130 billion in tariffs that have been collected or if repayments to the businesses that the paid those tariffs will have to be made. 

Chief Justice John Roberts wrote the majority opinion. "The president asserts the extraordinary power to unilaterally impose tariffs of unlimited amount, duration, and scope,” Roberts wrote for the court. “In light of the breadth, history, and constitutional context of that asserted authority, he must identify clear congressional authorization to exercise it." 

The ruling rolls back much of Trump's tariff plan, including reciprocal tariffs and the import taxes he imposed on goods from Canada, Mexico and China. However, many of the tariffs that apply to the autos sector like those on steel, aluminum, copper, vehicles and car parts all remain in effect. 

The ruling, however, will provide some relief for automakers, especially those with supply chains in Asian countries. That said, Americans should not expect the prices of their vehicles to go down overnight. The full ramifications of the Supreme Court's ruling will take time to take effect. 

Not only that, but with only supply chains seeing relief, the reductions in cost will be smaller than if Trump's tariffs were thrown out whole cloth. According to Automotive News, price changes in cars varied wildly based on where the cars were assembled, but cars from South Korea actually saw a price reduction when moving into the 2026 model year. 

However, the Trump administration has had time to patch together other ways to pursue tariffs. Those methods will take more time and won't allow the administration to move as quickly as it did under the International Emergency Economic Powers Act of 1977 Trump used to install tariffs initially. The court also noted "[the] IEEPA contains no reference to tariffs or duties" and that "[its] grant of authority to 'regulate ... importation' falls short." 

According to an estimate by U.S. Customs and Border Protection, the federal government has collected just over $313 billion in tariff revenue since October 2024. About $133.5 billion was tariff revenue collected under the emergency powers law. 

This is a developing story and will be updated.