Portside

Young people carried Zohran Mamdani in his victory in the mayoral primary, stunning establishment Democrats and reshaping the electorate. Nowhere was this more clear than the so-called “Commie Corridor,” where young voters had extremely high turnout.

Combining the wisdom of experience with the energy of youth can create powerful, lasting change.

Among the surprises this primary season were several high-profile upsets from the left. The lessons: The right candidate in the right district; Test. Don’t assume you know who the voters are; Go ahead and embrace the left; Redefine voter outreach...