Eight justices—the exception being Ketanji Brown Jackson—seem keen to rein in universal injunctions. But a majority also appear committed to averting Mr Trump’s radical departure from the constitution’s promise of citizenship. The justices could thread that needle in three ways.

Donald Trump’s lawyers seek to stop judges’ national block on executive order in case that could decide policy’s future.

President Donald Trump invoked the Alien Enemies Act against Tren de Aragua in mid-March, claiming that the gang is “perpetrating an invasion” into the U.S.