I'm reluctant to be a complete relativist about these things, even though I recognize that I'm biased. The fact is that a demogogue who wants to drive a wedge of fear between people (no need to state who I'm talking about) has a much harder time doing it in cities. All perspectives arent equal in this respect - some perspectives are based on ignorance and fear, and some are based on the actual experience of interacting with the kinds of people we're supposed to be afraid of.
As to the high correlation between population density and political affiliation, I don't see that as being particularly mysterious, even if it is a complex topic. And having recently hosted a fundraiser for a prominent progressive candidate I can attest that fear is being effectively employed across the entire electorate.
NYC is much larger than Manhattan.
Having lived in Manhattan I appreciate being able to visit when I like, for as long as I choose (working remotely).