President Trump is vowing to sign an executive order that would seek to end the right to U.S. citizenship for children born in the United States to noncitizens, a move most legal experts say runs afoul of the Constitution. The action, which Trump previewed in a television clip broadcast Tuesday, would be the most aggressive by a president elected to office pledging to take a hard line on immigration, an issue he has revived in advance of next week’s midterm elections.

President Trump issued three executive orders Friday aimed at overhauling the federal bureaucracy by making it easier to fire poor performers, sharply curtailing the amount of time federal employees can be paid for union work and directing agencies to negotiate tougher union contracts.