On May 2, 2025, the U.S. Department of Justice sued the state of Colorado, Attorney General Phil Weiser, Governor Jared Polis, the city of Denver, and several Denver officials to have a group of state and local laws in Colorado declared unlawful for impeding immigration enforcement and prohibiting cooperation between state and local law enforcement and federal immigration authorities. The lawsuit asks the U.S. District Court in Colorado to declare that several city and state policies are invalid, blocking their enforcement . The laws and policies in question generally restrict the ability of state and local government employees to help with immigration enforcement. Officials in Colorado deny the state is a sanctuary state and say they already work with federal authorities as required. Some local police departments say that working with ICE breaks trust in their communities and may make immigrants less likely to talk to the police if they believe it could lead to deportation. The suit asks the court to rule that these so-called sanctuary laws are illegal and a violation of the Supremacy Clause of the U.S. Constitution.

A spokesperson for the Colorado Attorney General’s Office released a statement saying their office “is committed to defending Colorado law and has done so successfully in the past in this area. We stand ready to do so again.”