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.

The U.S. Supreme Court has acted in a series of cases involving challenges to executive orders signed by President Donald Trump and actions by his administration since he returned to office in January.

The justices did not address the broader question about whether Trump officials can legally invoke the Alien Enemies Act to target alleged gang members.