Shattered glass and spilled beer coated the floors of the nightclub. More than 100 people had been taken into custody by federal immigration agents, and Colorado Springs’s mayor, Yemi Mobolade, had a decision to make.

Law enforcement officials said their operation in the Sunday morning darkness cleared out a club that was rife with drugs, guns and prostitution. Liberal voters who helped elect Mr. Mobolade, a Nigerian-born pastor and political independent, to lead their historically conservative city were disturbed by the mass arrest of so many immigrants.

Mr. Mobolade made his choice.

“This immigrant mayor says, if you’re here illegally and you’re committing a crime, there should be consequences,” he said in an interview. “You should be deported.”

The raid, led by the Drug Enforcement Administration, came the week after a large-scale operation in Florida that led to the arrests of more than 1,100 people. But this one was conducted in Democratic Colorado, in an increasingly purple city, Colorado’s second largest. The aftermath of the raid reflects the deep divisions over President Trump’s mass deportation efforts.

Mr. Mobolade and other mayors in Colorado, New York and Massachusetts have faced frustration and criticism from voters over their response to record-breaking migrant arrivals under President Joseph R. Biden Jr. Now they face a backlash from the left, as the Trump administration steps up its immigration crackdown and presses local officials to cooperate.

Some of Mr. Mobolade’s left-leaning voters felt betrayed by the raid. The arrests and a lack of information about what had become of the detainees unnerved many immigrants. What’s more, the city of Colorado Springs had participated by sending about 50 police officers to assist federal agents.