Attorney General Jeff Sessions slammed Chicago and other sanctuary cities in a speech in Miami on Wednesday.
Sessions suggested politicians in Chicago have prioritized politics over safety. He read aloud murder and shooting statistics for Chicago, a city that has been plagued by gun violence. He compared them with statistics in Miami, a city he praised for revoking its sanctuary city designation.
"Respect for the rule of law has broken down" in the city, he said. "In Chicago, I suggest the so-called sanctuary policies are one sad example of that."
Chicago Mayor Rahm Emanuel struck back. In a statement, he said the Trump administration could "not have picked a worse time to resume their attack" on immigrants. President Donald Trump has been criticized this week for comments he made about a deadly white nationalist rally in Charlottesville, Virginia, on the weekend.
"Chicago will continue to stand up proudly as a welcoming city, and we will not cave to the Trump administration's pressure because they are wrong morally, wrong factually and wrong legally," Emanuel said.
Emanuel's administration sued Sessions' Justice Department earlier this month in response to its plan to cut federal funds from sanctuary cities. San Francisco and California have both filed similar complaints.
The U.S. Conference of Mayors will file an amicus brief in support of Chicago's lawsuit and will invite mayors across the country to do the same, CEO Tom Cochran said in a statement Wednesday.
"The U.S. Conference of Mayors stands with Chicago Mayor Rahm Emanuel and deplores the attacks which the Attorney General leveled against him today and on previous days," Cochran said in a statement. "An assault on one mayor is an assault on all mayors."
WATCH: Rahm Emanuel on sanctuary cities
