President Donald Trump didn’t seem too happy with how Wednesday’s Supreme Court hearing over birthright citizenship went, but he reacted typically ― by making a big, fat, easily fact-checked lie.

Trump became the first sitting president to attend a Supreme Court hearing, but it didn’t seem like the majority of justices bought the administration’s argument that the 14th Amendment doesn’t actually guarantee citizenship to all people born in the U.S. regardless of their parents’ national origin ― even though that’s been the interpretation for more than 100 years.

And he may not attending any more hearings, based on his angry reaction to Wednesday’s session that he posted on his Truth Social platform shortly after storming out.

“We are the only Country in the World STUPID enough to allow ‘Birthright’ Citizenship!” he wrote.

The post was full of classic Trump trademarks, including arbitrary capitalization and, yes, falsehoods ― the easily fact-checked kind.