Bergen vs. Nassau vs. Westchester

[Tintrlvr]

One key difference is that Bergen doesn't have good public transit into Manhattan. NJ Transit does have some trains in the west of the county (the east of the county, closer to the city, is entirely without train service), but someone commuting into Manhattan then has to change trains at Secaucus. That definitely affects the type of people who move to Bergen as compared to Westchester (especially) and Nassau (to a lesser extent). The people who like to commute by train and move to NJ mostly move elsewhere, such as the wealthy towns in the west of Essex/east of Morris or to Union or Middlesex.

Westchester is definitely the home of "old money" as noted. And its wealthy voters are more Democratic (or at least less Republican), which may be related to being "old money". What makes Westchester more Democratic is hard to express, but there is a certain je ne sais quoi about Westchester that makes its wealthy voters different. If you grew up in the New York area, you just know what that is in your bones.

Long Island is basically more New Jersey, just like Staten Island, at least until you get so far out that you're starting to get to the second homes (about halfway across Suffolk -- the key divider is the Ronkonkoma LIRR station, which is the last station that has frequent commuter service into NYC), so Nassau and Bergen really aren't that different, culturally.