The U.S. Department of Justice has filed a federal lawsuit against the state of Colorado, the city of Denver, and several top officials, accusing them of obstructing federal immigration enforcement through so-called “sanctuary” policies. The suit, filed Friday in Denver federal court, claims these laws undermine national security and enabled violent gangs like Tren de Aragua to gain a foothold.
“The United States has well-established, preeminent, and preemptive authority to regulate immigration matters,” the lawsuit states. It argues that Colorado’s restrictions on cooperation between local law enforcement and federal immigration authorities directly interfere with federal mandates.
Central to the case is a controversial apartment complex in Aurora, where President Donald Trump previously alleged that the Venezuelan gang Tren de Aragua had taken over the building. While local officials pushed back on the scale of Trump’s claims, they acknowledged that the complex had been “terrorized,” with individuals linked to the gang involved.
The lawsuit singles out specific city ordinances and state laws that prohibit law enforcement from sharing information with or detaining individuals for Immigration and Customs Enforcement (ICE). The complaint argues that such policies “by intent and design interfere with and discriminate against the Federal Government’s enforcement of federal immigration law,” and requests the court to strike them down under the Supremacy Clause of the U.S. Constitution.
Named in the lawsuit are:
Colorado Governor, Jared Polis
State Attorney, General Phil Weiser
Denver Mayor, Mike Johnston
Denver Sheriff, Elias Diggins
In response, a spokesperson for Governor Polis said the state “will not comment on the merits of the lawsuit” but denied the “sanctuary state” label. “The State of Colorado works with local, state and federal law enforcement regularly… If the courts say that any Colorado law is not valid, then we will follow the ruling.”
Mayor Johnston’s office issued a stronger rebuke, stating: “Denver will not be bullied or blackmailed, least of all by an administration that has little regard for the law and even less for the truth. Denver follows all laws local, state, and federal and stands ready to defend its values.”
In March, Johnston testified before Congress about Denver’s approach to undocumented immigrants. During the hearing, Republican lawmakers criticized Johnston and other big-city mayors for refusing to hold individuals for ICE, claiming this endangered both law enforcement and the public.
Colorado Attorney General Phil Weiser’s office also vowed to defend state law. “We are committed to defending Colorado law and have done so successfully in the past in this area. We stand ready to do so again.”
The Trump administration, which recently returned to power, has renewed its hardline immigration stance. The president signed an executive order earlier this week directing the Justice Department to investigate sanctuary jurisdictions and potentially strip them of federal funding.
While there is no formal definition of a “sanctuary city,” the term generally refers to jurisdictions that limit cooperation with federal immigration enforcement, particularly in detaining individuals flagged for deportation by ICE. These policies are often rooted in concerns over public trust, safety, and local autonomy.
The lawsuit against Colorado follows similar legal battles the DOJ has launched against other cities, including Chicago and Rochester, New York, further escalating the national debate over immigration policy and federal-state authority.
