Chief Justice John Roberts has temporarily halted a lower-court order directing the federal government to return Kilmar Abrego Garcia from El Salvador, escalating what is quickly becoming one of the most closely watched emergency immigration disputes on the Court’s shadow docket.

The case arises from the government’s acknowledgment that Abrego Garcia was deported because of an “administrative error,” despite a lower court’s conclusion that he was lawfully present and could not be removed without due process.