Candidates affiliated with (or sympathetic to) the Democratic Socialists of America (the DSA) have recently won several Democratic primaries. Although this rise of the left takes a different form, it draws from prior social movements and Bernie Sanders' presidential candidacies. David Purucker has been both a close observer and a participant. He studied how the DSA makes decisions and organizes. Its electoral role draws from its relationship with the labor movement and other liberal causes. He says this year will raise a lot of questions about how the group responds to electoral success and failure.