This case could limit presidential authority on trade and has big implications for global commerce—if the court rules against Trump, it may curb future leaders from using similar tactics to justify tariffs.

Federal appeals court judges challenged President Trump's claim of expansive emergency powers to slap tariffs on the rest of the globe, suggesting during a high-stakes hearing Thursday that he's stretching the law too far.

A federal appeals court expressed doubt about President Trump's use of emergency powers to impose widespread tariffs, with judges questioning whether he overstepped legal boundaries during a high-profile hearing.