President Donald Trump erupted Sunday at the Supreme Court as its increasingly skeptical justices weigh in on the president’s authority to impose sweeping tariffs.

“So, let’s get this straight??? The President of the United States is allowed (and fully approved by Congress!) to stop ALL TRADE with a Foreign Country (Which is far more onerous than a Tariff!), and LICENSE a Foreign Country, but is not allowed to put a simple Tariff on a Foreign Country, even for purposes of NATIONAL SECURITY,” Trump wrote on his social media platform Truth Social. “That is NOT what our great Founders had in mind!”

The Supreme Court first heard arguments for and against Trump’s authority to impose tariffs last week, and a majority of the justices expressed skepticism at the Trump administration’s position, a skepticism that saw online betting platforms predict the court would strike down Trump’s signature trade policy.

Trump has grown increasingly panicked at the possibility of the Supreme Court striking down his tariffs, warning that the United States “could be reduced to almost Third World status” should the court rule against him. And on Sunday, that panic appeared to evolve into rage as Trump lashed out at the court online.

“The whole thing is ridiculous! Other Countries can Tariff us, but we can’t Tariff them???” Trump wrote. “It is their DREAM!!! Businesses are pouring into the USA ONLY BECAUSE OF TARIFFS. HAS THE UNITED STATES SUPREME COURT NOT BEEN TOLD THIS??? WHAT THE HELL IS GOING ON???”

Trump’s argument in defense of the tariffs rests on his administration’s reading of the International Emergency Economic Powers Act, a 1977 law that permits the president to impose tariffs in response to emergencies. The emergency, his administration has claimed, is the United States’ trade deficits with other countries. Whether the court will agree with that position is set to be determined in the coming days or weeks.