Why have top Democratic leaders failed to endorse rising star Zohran Mamdani?

New York's Governor Kathy Hochul has finally lent the city's mayoral nominee her support - but the party's top congressional leaders, both New Yorkers, have not

He's the hottest politician in the US, who managed to attract thousands of young and first-time voters to the Democratic party in his unexpected win in the New York City mayoral primary.

With the Democrats suffering from historically low approval ratings, one might have thought the party would rally round Zohran Mamdani, to learn lessons from the media-savvy 33-year-old and bask in his soaring popularity.