My take is that the democrat base is fired up. And, the GOP didn't mobilize...either because of apathy or just pissed at the way the US is being run. It is very much a referendum on Trump, and the first warning sign to his administration that the gravy train of his bullshit being rubber stamped by an ineffective congress will end in 12 months.
But Trump knows this already. Why else would he ask Texas to redistrict the state for the 2026 mid-term elections to give him (hopefully) more seats? Because he knows he cannot win on his record. I am well aware that things can change dramatically within the next year. But Trump will likely have triggered a recession by then. And he continues to do things that are unpopular for the average person not in the cult. And it appears that the cult's numbers are shrinking.
Every off-cycle American election, TERB and MERB members on the right or left go through these silly election postmortems. Midterms move away from the party in the White House. As further emphasis, off-off-cycle Governor elections in Virginia and New Jersey rarely give an indication of the future. As was noted above, Kamala Harris won both states. About one million less people in New Jersey and one million less people in Virginia voted last night as opposed to last November. No, people didn't stay home to protest Trump. There is just a high-propensity of truly motivated voters in off-off-cycle elections.
Now, as for Mamdani, I think he is tapping into a populous that is sick of seeing the rich become richer by basically standing on the necks of everybody else. They see rent prices rising, which doesn't really hurt the mega rich. And, for anyone saying the wealthy will leave...please. NYC is the place to be. It has the nightlife, the restaurants, the cultural stuff, sports and theatre. It is the financial hub, where deals are made and fortunes are won or lost. Where else would they go? Texas? Florida? lol. Maybe for the winter...
Markets and capitalism have become increasingly fast and mobile in the digital age. The idea that you have to be in NYC to make deals or trade is probably an outmoded concept. After all, why can't some financiers just meet in Connecticut or elsewhere.
NYC's high prices (of which I would argue have always been an issue) are the result of its success. NYC doesn't just attract domestic money it attracts global money. The global money has a lot of options.
The trick for Mamdani beyond the rhetoric is how does he do all the things he wants to do without hurting the tax base. NY State can't help him. The high tax rates and stagnating tax base have hamstrung the State's ability to raise further taxes.
As some commentators have noted, if you are in a career that doesn't pay enough to live a NYC lifestyle the smart thing is to move to a more affordable city. You know the phrase "fake it til you make it". At some point, you gotta stop faking it and move on.