[eschaton]

There's a few different dynamics that I think play a role here in why NYC has a uniquely high number of conservative neighborhoods within city limits.

The strongest by far is just the Hasidim and the other ultra-orthodox. Every single 80%+ Trump precinct in NYC is a Hasid or ultra-Orthodox area, as are most of the 70%-79% Trump areas.

Discounting those areas, there are mostly just "normal conservative" zones - areas where over half to two-thirds of people vote Republican. NYC has more of these than anywhere else, but they aren't unknown in other old urban areas. Philly has more than a few, Chicago has a couple, etc.

But NYC does stand out here, even considering its greater size. I think a few aspects play a role.

1. The sheer scale of the city mean that neighborhoods can develop with a critical mass of GOP-leaning occupations (like cops and firemen).

2. New York state had unique political dynamics which made the state Republican Party more competitive than it "should" have been for generations, which meant that the attachment of working-class white city dwellers to the Democrats was never as strong as somewhere like Boston or Chicago.

3. A lot of the zones which are pretty conservative are suburbs for all intents and purposes. Looking at most of Staten Island here for example. There's limited attractiveness for professional-class whites to gentrify these areas, which means as long as they don't shift to nonwhite neighborhoods they're going to lean GOP.

It is striking that if you compare southern Staten island to nearby parts of New Jersey it's way more GOP (some areas of Staten island were 75% Trump, while Middlesex County suburbs right across the Arthur Kill are generally at least narrowly Dem. However, this mostly seems to be because the NJ suburbs are way, way more diverse than southern Staten Island.