This week, the U.S. Supreme Court hears arguments on whether President Donald Trump has overstepped federal law with many of his tariffs.

A ruling against him could limit or even take away that swift and blunt leverage that much of his foreign policy has relied on.

Trump increasingly has expressed agitation and anxiety about the looming decision in a case he says is one of the most important in U.S. history.

He has said it would be a “disaster” for the United States if the justices fail to overturn lower court rulings that found he went too far in using an emergency powers law to put his tariffs in place.

Trump had said he wanted to take the highly unusual step of attending the arguments in person, but on Sunday said he had ruled it out, saying he didn't want to be a distraction.