Yeah there is. It's by choice, all by choice. And by that I mean the people with money want to live apart from the people without. You must live around here too huh? All the towns here have their own ethnic neighborhoods, or almost the entire town is an ethnic neighborhood. People here are most comfortable around their own kind, and when you've grown up here it's simply the way it is. It's not ideal by any means, but it's how it is.
As much as the segregation is racial, it's also economical. The two go hand in hand around here. It just so happens that the majority of people who cannot afford to live in the higher priced areas are minorities (including immigrants).
I live in North Jersey, grew up here and just got a job as County Correction Officer in Essex so I won't be leaving any time soon. So all that de facto segregation is just a normal part of life. When I think about it now that you mentioned those contrasting towns, it makes the tiny street I grew up on all the more special
You want a really interesting example? Montclair. You have the super-rich folk in Upper Montclair living in their multi-million dollar mansions, with celebrities thrown into the mix, and just a few blocks away on the other side of town you have a depressed "ghetto" (it's not really a ghetto but you know what I mean) that sees a lot more gang activity and violence than you'd think. And that "ghetto" is also bordered by Glen Ridge, another rich town.
Guess what the racial makeups of Upper Montclair, lower(?) Montclair, and Glen Ridge are? Rich, poor, well-to-do respectively.