>but when I see far more in common among constituents between Eastern WA and upstate NY than I see between Seattle and NYC I can’t help but feel that rural areas are far more united than cities are.

Do they actually have that much in common or is it out-group homogeneity?[1]. They would probably say all city dwellers are the same but obviously people from NYC don't have that much in common with people from SF beside some lifestyle commonality.

[1] https://en.wikipedia.org/wiki/Out-group_homogeneity

I’ve lived in various states all around the US and traveled for work often and honestly when I’m in most cities now I can’t tell them apart too terribly much besides native accents, weather, architecture, and some landmarks - the chain and corporate restaurants homogenized each place so much it’s a blur of random logos for myself. I can say the same for various rural areas I’ve visited though in a different way except there’s different chains (Dollar General being the one common logo) and naming conventions for run down local places that seem like Madlibs.