The key question in the Trump case is whether the 1977 International Emergency Economic Powers Act gives a president unfettered ability to set tariffs for any country, at any level, for as long as needed, whenever an emergency is declared at the president’s sole discretion.

U.S. President Donald Trump said on Sunday he will not attend the Supreme Court's upcoming oral arguments concerning the legality of his global tariffs.

Also at stake: trillions of dollars.

Voters will decide whether three justices who were elected as Democrats keep their seats for another 10-year term.