After a historic victory last fall, New York City Mayor Zohran Mamdani marked 100 days in office earlier this month. So far, it’s going pretty well: His approval numbers are broadly positive, he’s begun to deliver on some of his key campaign promises, and he weathered his first major challenge as mayor after NYC endured two serious winter storms earlier in the year. (He’s also successfully charmed President Donald Trump not once but twice .) Mamdani’s track record also suggests some questions for the Democratic Party as it heads into the midterms. Among them: Is Mamdani’s success a glimpse into the party’s future? How much of it can be replicated outside of New York or on a national stage? And how much is the party willing to listen? Ben Rhodes was a deputy national security adviser and close aide to Barack Obama. He’s now an author and co-host of Pod Save the World , a podcast about world news and foreign policy.…