The US Supreme Court told Donald Trump on February 20 that the tariffs he has used to try and bend the world to his will are unlawful. Tariffs are taxes and it is not for the president to impose them. According to the US constitution, Congress holds the power of the purse.
Trump relied on the terms of a 1977 law designed to address national emergencies, the International Emergency Economic Powers Act, to impose the majority of his tariffs. The court held that this law did not provide Trump with the legal authority to impose them.
In a post on social media following the court’s decision, Trump called the justices who ruled against him a “Disgrace to our Nation”. And he has subsequently announced that he will rely on another law, section 122 of the 1974 Trade Act, to impose worldwide tariffs of 15%.