Left-wing DSA candidates keep winning Democratic primaries, and it's a growing threat to the party's old guard heading into 2028.

• DSA-backed newcomers are ousting long-time incumbents, including one who beat a 30-year Congress member in Colorado.
• The winning coalition is mostly about age, not race — young renters, priced out of buying homes, are the base.
• These candidates are now also pulling in older and non-white voters who used to reject the left, thanks to a decade of door-knocking and organizing.
• Zohran Mamdani has become a movement figurehead, able to pass his support on to other candidates in a way Obama and Trump could not.
• The message centers on affordability and fighting big money, not identity politics, which widens the appeal.

Outlook: Expect the left to keep testing whether this coalition can win statewide in places like Michigan and Maine, with 2028 as the real target.