The Wary, Warming, Wildly Consequential Alliance of Ocasio-Cortez and Mamdani

Zohran Mamdani was not asking for an endorsement. This seemed wise. Because Alexandria Ocasio-Cortez was not offering. But sitting last year, at Mr. Mamdani’s request, at a kebab house in Queens — where he shared that he would like to be mayor of New York City — the nominal very-long-shot hoped that the national very-big-shot might at least think well of the idea. “It all started in a similar way that my race had started,” Ms. Ocasio-Cortez recalled at a joint rally many months later. “We don’t have an entire political establishment behind us. But we know that running is...