"This means that there is hope that they can actually have their claim heard in front of an immigration judge while they remain in the U.S. side of the border rather than still in danger."
The Border Angels organization supports 17 migrant shelters in Tijuana and provides legal aid to residents.
About 70,000 people were enrolled in the program, formally known as Migrant Protection Protocols, after President Donald Trump launched it in 2019 and made it a centerpiece of efforts to deter asylum-seekers.
After Biden's suspension of the program, Homeland Security Secretary Alejandro Mayorkas ended it in June 2021. In October, the department produced additional justifications for the policy's demise, to no avail in the courts.
The program resumed in December, but barely 3,000 migrants had enrolled by the end of March, during a period when authorities stopped migrants about 700,000 times at the U.S.-Mexico border.
Democratic-led states and progressive groups were on the administration's side. Republican-run states and conservative groups sided with Texas and Missouri.
The case is Biden v. Texas, No. 21-954.
KQED's Farida Jhabvala Romero contributed reporting to this story.