General Discussion

I agree that is was not a "progressive landslide". I think had Mamdani performed better, and had Sliwa pulled more from Cuomo rather than bleeding support to him, it would've been a landslide election that would translate to what you mean by a more generalized progressive landslide.

Where I disagree, and I'm even sure if we do disagree, is that Mamdani's victory elucidated a manner of campaigning that is fresh and might be conducive to winning elsewhere. He showed that social justice populism is a strong foundation.

Additionally - and I think this is a point that hasn't really been discussed, Mamdani ran very much a New York City focused campaign. Significantly more than any mayor in my lifetime except Giuliani (from a darker perspective, i.e. New York is full of these bad things and I'm going to fix them!). In effect, he ran a "NYC First" campaign, and you are right that politics is local. In this sort of NY-pride sort of way, I think Mamdani shared some tactics with Trump's MAGA.

Mamdani won an election that he, conceivably, could have lost. His win is data we should analyze and use moving forward.

Also, he has forced Gov. Hochul to rethink her frustrating centrism, which will probably bode well for her as well.