The US Supreme Court ruled Thursday in a 5-4 decision that US President Joe Biden can end former President Donald Trump’s Migration Protection Protocols (MPP) policy, also known as the “Remain in Mexico” policy. This overturns a US Court of Appeals for the Fifth Circuit ruling that kept the MPP policy in place.

The MPP, originally announced in 2018 and implemented in 2019, allowed the US government to return undocumented immigrants to Mexico as they awaited their asylum hearings. When Biden took over office he suspended the program which followed with Homeland security terminating the controversial policy. Texas and Missouri sued claiming that the termination violated the Immigration and Nationality Act and the Administrative Procedure Act. The district and appellate court both sided with Texas and Missouri.

The Supreme Court found that the appellate court was incorrect in saying that federal immigration law necessitates sending immigrants back if the US is unable to detain them. Chief Justice Roberts stresses that the law only says that the government “may” send immigrants back and that this is not a requirement.

The court also noted the potential consequences the policy would have on foreign affairs with Mexico. Justice Roberts said the policy imposed “a significant burden upon the Executive’s ability to conduct diplomatic relations with Mexico.”

Justices Kavanaugh, Sotomayor, Kagan, and Breyer joined Roberts’ majority opinion. Justices Alito, Barrett, Gorsuch, and Thomas dissented.