A federal judge blocked the Trump administration on Thursday from requiring 20 mostly Democratic states to cooperate with federal immigration enforcement in order to receive billions of dollars in transportation funding.

Chief U.S. District Judge John McConnell issued a preliminary injunction that barred the administration from enforcing the new immigration rules for “the States and their governmental subdivisions” while the lawsuit plays out in court. He said that requiring the states to cooperate with Immigration and Customs Enforcement to receive congressionally appropriated transportation funding violated the Constitution.