The leading progressive senators will speak at a sold-out event at the 3,500-seat Orpheum Theater at 7:30pm EDT, after Sanders separately attends a 2:00pm Q&A at the Edward M. Kennedy Institute in Dorchester and a book signing at the Massachusetts Institute of Technology (MIT).
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Warren and Sanders have emerged as some of the leading voices opposing the Trump administration. Friday's rally is expected to cover issues such as criminal justice reform, immigrants' rights, and wage inequality, according to the Boston Globe.
It will also help start both of their 2018 reelection campaigns on a strong note. And David Hopkins, a political science professor at Boston College, told the Globe that Sanders' 2016 presidential bid challenging Hillary Clinton could serve as a template for Warren if she decides to run in 2020.
"If she does run, she would likely pattern her presidential campaign after Sanders' 2016 candidacy and seek to inherit the faction of Democrats who supported Sanders last year," he said, calling the Vermont socialist a "kindred spirit in the Senate" for Warren.
Erin O'Brien, chairwoman of the political science department at the University of Massachusetts Boston, added, "The guy, who is not even a Democrat, is being treated like a rock star in deep-blue Kennedy Massachusetts, and it's because he is a rock star."
Friday night's rally is organized by Our Revolution, the political action organization that spun off of Sanders' presidential bid, as well as Raise Up Massachusetts, a coalition of grassroots groups that has advocated for higher minimum wage and paid sick leave.