Despite a recent U.S. Supreme Court ruling limiting lower court judges’ power to block President Donald Trump’s policies through nationwide injunctions, a federal judge on Thursday blocked the administration from enforcing an executive order restricting birthright citizenship.

U.S. District Judge Joseph Laplante of Concord, New Hampshire, a George W. Bush appointee, issued the ruling after immigrant rights advocates sought class action status in a lawsuit representing children whose citizenship could be threatened by the order. Laplante granted class status and issued a nationwide injunction blocking enforcement, calling the decision “not a close call.” He emphasized that allowing the order to take effect could irreparably harm children by stripping their U.S. citizenship.

“That’s irreparable harm, citizenship alone,” Laplante said, according to Reuters. “It is the greatest privilege that exists in the world.” He temporarily paused the ruling to allow the administration time to appeal and promised a written decision by the end of the day.

The lawsuit, filed by the ACLU and others, came hours after the Supreme Court’s June 27 ruling limiting nationwide injunctions. Despite the ruling, the plaintiffs argued that class action lawsuits remain an exception allowing judges to block policies nationwide. The judges issuing injunctions found Trump’s order likely violates the 14th Amendment, which guarantees citizenship to anyone born in the U.S. and subject to its jurisdiction.

The Department of Justice insists the order complies with the Constitution and has asked the court to deny class certification. The Supreme Court ruling did not address the legal merits of the birthright citizenship policy itself.