With the three liberal justices in dissent, the court said the administration likely violated federal law in its efforts to rescind the program informally known as Remain in Mexico.

The justices said in their unsigned decision that the Biden administration appeared to act arbitrarily and capriciously by rescinding the policy, formally known as the Migrant Protection Protocols. They also cited last year’s decision in the Department of Homeland Security v. Regents of University of California case. That decision blocked the Trump administration’s effort to undo the Obama-era program protecting young immigrants that came to the U.S. as children.

Immigration advocates, including the American Immigration Council said Remain in Mexico is a dangerous policy for thousands of people seeking humanitarian aid.