United States of America v. State of Colorado, et al.

In a lawsuit brought against Colorado and Denver by the federal government, the ACLU of Colorado filed an amicus brief defending state and local laws that limit the diversion of their resources for the purpose of federal civil immigration enforcement. The brief argues that these laws are good policy, as they protect public safety and the functioning of state government, keep state actors within constitutional bounds, and promote the overall well-being of our communities and economy.

The federal government filed a lawsuit challenging a set of Colorado and Denver laws that limit the diversion of their resources for federal civil immigration purposes. The federal government alleges that such laws violate the Supremacy Clause of the U.S. Constitution by discriminating against the federal government and obstructing the enforcement of federal laws. The Colorado and Denver Defendants moved to dismiss the lawsuit in its entirety, arguing that the laws are well within their constitutional authority.

The ACLU of Colorado submitted an amicus brief in support of the Defendants’ motions to dismiss. The brief describes some of the reasons why jurisdictions like Colorado and Denver choose to limit their law enforcement agencies’ participation in immigration enforcement. First, the challenged policies protect public safety and the functioning of state government by mitigating the fear that reporting a crime, showing up to court, or cooperating with police will lead to someone’s deportation. Such policies also ensure that local law enforcement agencies can allocate scarce resources for their core mission of enforcing criminal law. Second, by guarding against constitutional violations, such as holding people in jail past their release date or engaging in questionable immigration enforcement tactics, the challenged policies protect Coloradans’ liberties while limiting state and local officers’ exposure to liability. Finally, the challenged policies protect the substantial contributions that immigrants make to the tax base and overall economic well-being of our communities.

Media:

"Trump’s DOJ sues to block Colorado and Denver's ‘sanctuary laws,'" CPR News, May 2, 2025.