Trump’s executive order, signed in January, seeks to deny citizenship to children who are born to people who are living in the U.S. illegally or temporarily. It is part of the hard-line immigration agenda of the president, who has called birthright citizenship a “magnet for illegal immigration.”

Plaintiffs challenging the order used a class-action lawsuit to get around the Supreme Court’s ruling banning nationwide injunctions.

The judge also granted the case class-action status after the Supreme Court limited judges' ability to block orders nationwide through other means.