A major court ruling has effectively stripped legal immigration status from some 400,000 people in the United States, opening the door for the Trump administration to deport them en masse. A 2-1 ruling by the United States Court of Appeals for the Ninth Circuit on Monday sided with the Trump administration, saying it acted legally when ending protections that have allowed hundreds of thousands of people to live and work in the U.S.. It affects those with “temporary protected status,” which has allowed people to stay in the country after fleeing wars or natural disasters in Haiti and El Salvador. The New York Times reports the Trump administration has argued that those emergency conditions no longer exist in many cases, and should no longer be considered. The decision is not effective immediately—the Trump administration has agreed to maintain protections until at least March 2021. A new administration could also choose to keep the program.