The Supreme Court is stepping into a major legal battle that could redefine presidential power in the U.S. At stake? President Trump’s sweeping global tariffs imposed under a powerful emergency law — the International Emergency Economic Powers Act (IEEPA).

Chief Justice John Roberts on Tuesday allowed the Trump administration to freeze billions in foreign aid payments for now, putting on hold a lower court ruling that required officials to spend $4 bill...

If the tariffs are struck down, the U.S. Treasury might take a hit by having to refund some of the import taxes it’s collected, Trump administration officials said.