This time, she spoke to two gun violence prevention groups that are growing by the day: Moms Demand Action and Students Demand Action.
Moms Demand Action, which started 10 years ago, has grown to 10 million members nationwide. Chicago's Valerie Burgest became one of its original volunteers after her son, Craig, was murdered in 2013.
"People wouldn't even talk to us as mom volunteers. And now, they not only talk to us, they seek us out. They want our support," Burgest said.
Moms in the red shirts have the full support of the Biden administration.
"You put the pressure on the system, so the system had to hear the voices and respond in some way," Harris said.
Harris credited historic gun reform legislation with their activism. She was the keynote speaker for the Everytown for Gun Safety conference at McCormick Place.
"We are counting on you. You are everything," Harris said.
Erin DeSantis, 17, was hand-picked to ask Harris a question. She and other students met with the vice president for a private conversation before the event.
"She is very human, like the rest of us. There was no big fanfare around," DeSantis said.
The Biden administration sees the gun violence issue as key to galvanize the youth vote. It's one the Biden/Harris ticket knows it needs to win in 2024, and a vote Harris says is vital for the passage of common-sense gun laws
"When your generation starts to vote in your numbers, I see this changing completely," Harris said.
"We are so up for it. We are so tired of living all through all these things, every single day. Once I turn 18, I'm ready to register to vote," DeSantis said.
While Harris rallied the crowd, she made no mention of Friday's Illinois Supreme Court ruling upholding the state's assault weapons ban.
Harris visit was short. After speaking for a half hour, she headed back to Washington, D.C.
The conference continues through the weekend. On Saturday, Gov. JB Pritzker is expected to be there, signing some gun reform legislation.