Shakur was convicted of the 1973 murder of a New Jersey state trooper when she was in the Black Liberation Army. After escaping from prison in 1979, Shakur fled to Cuba.
"Now I came here not to talk at you -- it's gonna be a long and powerful day," Watkins said. "But I want you to do something with me. I'm gonna actually have you participate with me in repeating some words from a leader by the name of Assata Shakur. So if you could stand up -- if you can't stand, it's okay -- but I want you to repeat after me."
Watkins then quoted Shakur, pausing to let attendees repeat after him: “It is our duty to fight for our freedom. It is our duty to win. We must love each other and support each other. We have nothing to lose but our chains.”
Eight 2020 Democratic White House contenders Cory Booker, Julián Castro, Beto O'Rourke, Amy Klobuchar, Bernie Sanders, Elizabeth Warren, Jay Inslee and Kirsten Gillibrand spoke at the conference.
None of the candidates referenced the chant during their speeches.