The DOJ sued the state of Colorado and the city of Denver for supposedly getting in the way of federal immigration enforcement.

The case, which was filed Friday in Colorado District Court, says that the state and its largest city are breaking the Constitution by having “sanctuary laws.”

“The United States has well-established, preeminent, and preemptive authority to regulate immigration matters,” the suit says.

Sanctuary towns are places that try to protect people who are here illegally and don’t work fully with federal authorities to enforce immigration laws.

Similar lawsuits against “sanctuary policies” have been brought by the Department of Justice in Rochester, New York, and Chicago.

The department’s lawyers say that Colorado’s “sanctuary policies” let the Venezuelan gang Tren de Aragua (TdA) take over an apartment complex in Aurora, a suburb of Denver.

Local officials have said that President Trump’s claims that the gang had taken over big parts of the city were exaggerated, but they did say that the apartment complex was being terrorised by people with ties to TdA.

The people being sued in Colorado are Gov. Jared Polis, the state Legislature, Denver Mayor Mike Johnston, and Colorado Attorney General Phil Weiser.

Polis’s office said that Colorado is not a sanctuary state and that they work with local, state, and federal police on a daily basis.

A spokesman for the state told The Associated Press, “If the courts say that any Colorado law is not valid, then we will follow that ruling.” “We are not going to comment on the merits of the lawsuit.”

Republicans in Congress have tried to get city leaders in Democratic-led areas to follow the Trump administration’s immigration policies, which include threats to remove a lot of people.

Last month, Republicans in the House asked the mayors of Denver, Boston, New York City, and Chicago to appear before the Committee on Oversight and Government Reform. But the mayors fought back and said that their cities were safe, welcome places and not lawless danger zones. The mayors also asked Congress to make changes to immigration law.