The tall one with the bullhorn and shiny bracelets did the chanting. The two others, carrying signs, repeated what the bullhorn man said as they walked up and down the sidewalk.
The one thing they didn't chant: "A fair trial for Jason Van Dyke," the white cop charged with murder in the shooting death of McDonald, the black teenager.
Inside the courthouse on Wednesday, Judge Vincent Gaughan and lawyers continued to select a jury.
"Fair trial?" said the bullhorn man, Brother West Side, whose real name is Bobby Scott. "You see the video? He shot him 16 times. I'm surprised that God didn't paralyze his arm. Evidence? Fair trial? The video was on national TV. Sixteen times!"
This heater case has already cut into the careers of police officers accused of trying to cover up what happened when Van Dyke shot McDonald 16 times.
And it has also cost the mayoral career of Rahm Emanuel, who pulled the plug on his re-election bid rather than run a campaign while answering questions about why his administration suppressed the release of the McDonald shooting video.
In that bright sunshine, a few cops found patches of shade from which to watch the demonstrators.
"That's a cast of thousands," said one.
"You going to talk to these guys?" asked another.
Yeah, I said.
"Enjoy yourself," he said.
With Brother West Side was Jack Dicter, who finished most sentences with "know what I'm sayin'?" and Jair Gamaliel Olivares, 23, an asphalt worker who hopes to teach high school computer science.
They're just starting to know each other.
I pestered them about the pretrial publicity and the racial politics and asked this: Can Van Dyke get a fair trial?
"Fair trial is when he's convicted," Dicter said. "I can see two shots, but 16 times? That's overkill, know what I'm sayin'?"
Olivares said he loved McDonald but had never met him.
"It's a Christ-like love. You love him the way you love all humanity," he said. "And nobody deserves to die."
What about a fair trial for Van Dyke?
"The way you get a fair trial is by not putting me on the jury," Olivares said.
He paused, then asked me:
"Are you really running for mayor?"
Journalists from around the country will descend upon Chicago to walk up those courthouse steps and craft sweeping stories of politics and race in the city by the lake, stories about a case of a white cop killing a black teenager, and about the mayoral politics playing out behind it.
A few might get the politics half right.
But there was no grand sweep on those steps Wednesday. There were mostly regulars involved with other cases, enjoying the sun on a glorious day.
Young prosecutors and bailiffs grabbing smokes. Detectives in their blue testimony suits and shined black oxfords. Old overworked criminal defense attorneys with their suit trousers hiked up, as if they were in some ad for "Better Call Saul."
The facial expressions were remarkably the same, like a slice of yesterday's ham, the look of people who've seen too much.
A woman sat on a stone bench having an early lunch, a hot dog and a bag of Cheetos. She watched the three motley protesters below.
She was pleasant. She has worked in the courthouse for years. She asked not to be named, and I respected that.
"I don't think it will be bad until the verdict comes in," she said. "Hopefully it's a good verdict, otherwise the city will go up in a roar. If it's a bad verdict, things will go crazy."
And what is a bad verdict?
"If they find him not guilty, people might get upset."
It's the truth. There is that worry. The fact is, everyone who hasn't been under a rock thinks about what will happen if Van Dyke walks.
"I don't want to talk about color or race, there's good and bad people, even our police officers, and the bad ones are overshadowing the good now," she said. "But 16 bullets in a boy's body? Ah, come on, 16 bullets? He was no threat. The video â€¦"
Her voice trailed off and disappeared. We sat there and didn't say anything as Brother West Side shouted below.
When her voice came back it had changed.
"My son was killed a year ago," she said. "Not by a police officer. By a kid who thought my son had money. He didn't have money. Now he's dead."
Her son had two little boys. Now she raises them.
"I have a daughter, but you don't worry about girls in the way you worry about boys in Chicago. I never thought like I do now that my son was killed. My whole mind is different. I understand our police are under pressure, but from that video, he was no threat."
"You're in the big hospital waiting room, you're OK, but when they're going to take me into the little room, I know why you're going to take me for," she said. "To tell me what I didn't want to know. When they take you into that little room, you know why."
She began to weep.
"I hope this city gets better. There's so much pain in Chicago now. People are afraid of police. They're afraid of everything, everywhere. It's just too much pain. There's just so much pain all over."