Friedberg’s prediction had two key components:

1. Starting point: that the June 2025 New York City mayoral Democratic primary would mark the beginning of a wave of democratic socialist / left‑populist victories in major U.S. cities.
2. Trajectory: that over the next several election cycles there would be a growing wave of such candidates winning major municipal offices.

What has happened so far (through Nov 30, 2025):

• On June 24, 2025, Assemblymember Zohran Mamdani, a self‑identified democratic socialist and member of the Democratic Socialists of America (DSA), won the New York City Democratic mayoral primary. 【0search18】 He is explicitly described as a democratic socialist and DSA member. 【1search18】【1search0】
• On November 4, 2025, Mamdani won the general election and is now mayor‑elect of New York City, the largest U.S. city, running on a democratic socialist platform. 【3search19】
• In the 2025 Seattle mayoral election, progressive activist Katie Wilson defeated incumbent Bruce Harrell; she is widely described as a democratic socialist or self‑proclaimed socialist and ran on a left‑populist platform focused on affordability, homelessness, and taxing the wealthy. 【3search24】【2news18】【2news13】【2search0】
• A running list of elected socialist mayors in the U.S. now includes NYC and Seattle (terms beginning 2026) alongside earlier DSA‑aligned mayors in smaller or mid‑sized cities, indicating that socialist mayors exist but only some of these wins occurred after June 2025. 【1search20】

Why the prediction is not yet judgeable:

• The “beginning” part of his claim is broadly consistent with events: a DSA democratic socialist winning the NYC primary (and then the mayoralty) in June–November 2025, followed by a democratic socialist winning in another major city (Seattle) the same cycle, does look like the start of a left‑populist surge in big‑city municipal politics.
• However, he explicitly forecast a “growing wave over the next several election cycles.” As of November 30, 2025, we have seen only one main municipal election cycle (the 2025 local elections). We don’t yet have evidence from multiple future cycles to confirm whether this is a sustained, growing trend or a one‑cycle peak.

Because the time horizon (“next several election cycles”) has not passed and we cannot yet see whether the trend grows, stalls, or reverses, the prediction cannot be definitively rated as right or wrong at this point. It is directionally supported so far but still too early to call, so the appropriate status is inconclusive.