In February 2026, the Supreme Court struck down the Trump administration’s expansive tariff regime, holding in Learning Resources, Inc. v. Trump that the International Emergency Economic Powers Act (IEEPA) does not authorize the president to impose tariffs on imports from every country in the world. Within weeks, the U.S. Trade Representative (USTR) responded by launching two sets of investigations under Section 301 of the Trade Act of 1974, which authorizes investigation into other countries’ practices that may burden or restrict U.S. commerce.These latest investigations collectively cover almost all trade into the United States (roughly 99 percent). They involve alleged structural…