A group of 50-60 demonstrators hurled obscenities at police and even scuffled with some residents in the historic Bridgeport neighborhood.
For the first time this week, some officers responded by putting on protective helmets and face shields. Some protesters wore masks, which offer anonymity and perhaps confidence.
Protesters put police to the test, bypassing their lines, sitting in the streets and shouting.
Decrying everything from NATO-backed wars to local police torturem, they marched in the South Side neighborhood and encountered some residents who were unhappy with their message and their tactics.
"They're nuts. I don't know what they are doing. They shouldn't even be in the neighborhood," said one resident.
One protester wouldn't give her name, but she was among the few who agreed to talk.
"Victory for me is informing, educating and radicalizing the public," she said.
No one was arrested.
Just two hours before Tuesday night's demonstration, Police Superintendent Garry McCarthy told ABC7 his officers will have to have a thick skin in the coming days. They won't be deployed in riot gear, at first. Any tear gas orders will have to come from him. It's an intentionally non-confrontational strategy.
"If people want to throw rocks, cause mayhem, that's going to be a perception issue that we could bring that under control very, very quickly. But again that's not the image we want people to see of the city of Chicago," he said.