What may be the biggest battle yet in Donald Trump's trade war is about to begin.
The Trump administration heads to the US Supreme Court on Wednesday, facing off against small businesses and a group of states who contend most of the tariffs it has put in place are illegal and should be struck down.
If the court agrees with them, Trump's trade strategy would be upended, including the sweeping global tariffs he first announced in April. The government would also likely have to refund some of the billions of dollars it has collected through the tariffs, which are taxes on imports.
The final decision from the justices will come after what could be months of poring over the arguments and discussing the merits of the case. Eventually they will hold a vote.
Trump has described the fight in epic terms, warning a loss would tie his hands in trade negotiations and imperil national security. He has even suggested he might take the unprecedented step of hearing the arguments at court in person.
If we don't win that case, we will be a weakened, troubled, financial mess for many, many years to come, he said.
The stakes feel just as high for many businesses in the US and abroad, which have been paying the price while getting whipped about by fast-changing policies.
Trump's tariffs will cost Learning Resources, a US seller of toys made mostly overseas and one of the businesses suing the government, $14m (£10.66m) this year. That is seven times what it spent on tariffs in 2024, according to CEO Rick Woldenberg.
They've thrown our business into unbelievable disruption, he said, noting the company has had to shift the manufacturing of hundreds of items since January.
In deciding this case, the Supreme Court will have to take on a broader question: How far does presidential power go?
Legal analysts say it is hard to predict the justices' answer, but a ruling siding with Trump will give him and future White House occupants greater reach. Opponents say the law authorises the president to regulate trade but never mentions tariffs, asserting that only Congress can establish taxes under the US Constitution.
Three lower courts have ruled against the administration. After the Supreme Court hears arguments on Wednesday it will have until June to issue its decision, although most expect ruling by January.
In Switzerland, chocolatier Daniel Bloch expressed uncertainty over the outcome. His company Chocolats Camille Bloch is grappling with the cost of new tariffs, which has led to keen concerns over sustainability of profits.
The European Parliament is also holding back ratifying trade agreements with the U.S. until after the Supreme Court's decision.
The implications for an estimated $90bn worth of import taxes hang in the balance, making it a pivotal moment in both U.S. trade policy and presidential power.
