Sen. Bernie Sanders (I-VT) pressed the Democratic Party to champion the socialist policies espoused by New York Assemblyman Zohran Mamdani, who recently clinched a victory in the Big Apple’s Democratic mayoral primary.

Sen. Bernie Sanders on Zohran Mamdani defeating Andrew Cuomo in the NYC mayoral primary. CHRIS HAYES, MSNBC HOST: You know, one thing I think is that, I'm curious what you think of this theory. I think one thing that happens in campaigns is people get risk averse the more sort of backing they have,