The Supreme Court on Wednesday will weigh whether President Trump lawfully invoked the International Emergency Economic Powers Act to impose tariffs on imports from more than 100 countries, a sweeping step he says is vital to defend the United States. A decision in weeks or months could reshape costs for businesses and consumers and affect his second-term agenda. A dozen states and small firms say the tariffs forced price hikes and staff cuts. The case, a legal tossup, is the first in his second term to test the lasting merits of a major priority.

Prepared by Lauren Mitchell and reviewed by editorial team.