Critics expressed fears that the court’s ruling would embolden Trump to further test the limits of his statutory authority to enforce border-control laws without explicit approval from lawmakers. Aides have promised new measures ahead of the midterm elections in November, and Trump ruminated this week about the power to turn away unauthorized immigrants without offering them due-process rights.

“Who’s going to be next?” asked Sen. Mazie Hirono (D-Hawaii), whose state brought the case against the travel ban. “Is the president going to issue an executive order against Mexicans? Is he going to issue an executive order against people from Honduras? Guatemala? What’s next?”