The Ninth Circuit grappled with the president’s tweets and agency discretion during oral arguments on the administration’s decision to rescind the Obama-era immigration policy known as Deferred Action for Childhood Arrivals.

U.S. District Judge William Alsup of the Northern District of California partly blocked the Trump administration’s decision in January, ordering the government to continue processing renewal applications for existing DACA recipients. The Supreme Court later rejected an appeals request by the Justice Department, sending the case back to the Ninth Circuit.