The Supreme Court ruled on Thursday against a bid from President Trump to end the Obama-era immigration program known as Deferred Action for Childhood Arrivals, or DACA.
The program shields certain young immigrants from deportation, allowing them to receive work permits. There were roughly 700,000 "Dreamers" in the program when Trump ordered it to wind down in 2017.
Chief Justice John Roberts said in his opinion that the administration's termination of the program was "arbitrary and capricious" and a violation of federal governing administrative procedures. Roberts, a conservative, was joined in his opinion by the court's four liberals.
Trump and his legal team have argued that former President Barack Obama did not have the authority to implement the program in the first place. The argument and Trump's effort to end the program were overturned by courts in New York, California, and Washington, D.C.