Westchester and Nassau

[Tintrlvr]

If you're from the NYC area, you just know.

White people in Westchester are wealthier, more highly educated and, maybe most significantly for this purpose, WASPier in background and social attitudes than white people in Nassau. There's a big prestige difference between the two: people who care about prestige live in Westchester, and people who don't live in Nassau. Westchester is more people who (or whose parents or grandparents) lived in Manhattan before they moved to the suburbs while Nassau is more people who (or whose parents or grandparents) lived in Queens before they moved to the suburbs. The Italian percentage is much higher in Nassau than in Westchester. The Jewish percentages are probably similar, but it's different sorts of Jews: more Reform in Westchester vs. more Sephardis, Orthodox and Persian Jews in Nassau. (There are no areas like the Five Towns that are dominated by Orthodox Jews in Westchester.)  There's also some development history difference: more houses in Westchester tend to be pre-WWII, while Nassau housing is mostly post-WWII.

[Tintrlvr]

From American Factfinder.

College graduates:

Westchester  46.1%
Nassau  42.3%
Suffolk  33.5%

College graduates, NHWs:

Westchester  56.3%
Nassau  46.8%
Suffolk  37%

Graduate or professional degree:

Westchester  22.7%
Nassau  19%
Suffolk  15.1%

Per capita income:

Westchester  $48,487
Nassau  $42,949
Suffolk  $33,756

Per capita income, NHWs:

Westchester  $64,730
Nassau  $51,067
Suffolk  $43,825

This shows the important differences. It's the NHW figures that matter, and they show a substantial difference. The black and Latino voters are not much different in the two counties, which smoothes over the large differences between whites when you look at overall statistics (and also income/education affect voting patterns among blacks and Latinos both less and differently than among white voters).

Also shows why Suffolk was more Trump-friendly than Nassau.