As someone who doesn't live in the USA I've always wondered: NYC (heavily DNC?) routinely seems to do things that are far more inhuman and racist than anything the GOP does, how come it never generates the same level of outcry?
The mayor of New York was a Republican from 1994 to 2014. If your impression about city policies were accurate, that would not count against the Democratic party in the way you seem to imply.
But I don't think your impression about the city is all that accurate to begin with. New York being the largest and highest profile US city, you hear more news about it than about other parts of the US, but you shouldn't be drawing inferences about the rest of US from the absence of news that reaches you.