In the big cities, who votes Republican?

[Sam Spade]

Well, in NYC, to really overgeneralize...

In black areas - no one.  Really.  Blacks typically talk a whole lot less politics than you might think, and tend to view whites as one whole group, regardless of whether whites are liberal or conservative.

In Hispanic areas - it's usually the religious ones and then usually the Protestant ones (few and far between unlike down South).  Of course, they're mostly Ricans, so that means Republicans are rare.

In Asian areas - the Chinese are Democratic and insular.  Oh, and they're insanely cheap.  Don't know their community well - I don't speak Chinese though.  Yes, there are other Asian groups - I don't really care about them.

In white, non-ethnic/non-conservative Jew areas (Yuppie/hippie land = my world), they're the ones who don't talk when someone proceeds to espouse to them the wonders of the progressive agenda, which they usually do off the cuff without even asking.

In white, ethnic/conservative areas, they aren't the minority.  Well, not at the national level - local level, yes.