To be honest, I'm just not used to living in a place with ethnic division along geographic boundaries. It may exist, but I've not personally seen it so yea, it's hard to imagine. Not saying it doesn't exist, but you asked the question to me personally.
Ah well, it’s a significant problem in many parts of America. Pretty much every metropolitan area has ethnic segregation to some extent among geological lines. This is due to a variety of factors- white flight, a long history of oppression and a fairly recent desegregation movement, towns where black people weren’t allowed to stay the night, generational discrepancies exaggerating existing effects, etc.
It’s fairly normal for there to be a wide variety of reasons why specific areas are predominantly one or another ethnicity.
