If you define “next door” by time to reach, then NYC had that contrast ever since the street car/subway was available. Extreme wealth, spend a nickel (or walk

If you define “next door” by time to reach, then NYC had that contrast ever since the street car/subway was available. Extreme wealth, spend a nickel (or walk a block) and then see wretched poverty. So nothing really new…it was/is the reality of Manhattan since the late 1800s. And the future of “the US” is actually your projected future for a fairly tiny geographic region of densely urban US, something the other 95+% of Americans look at with a combination of bemusement and amazement. It’s been a few decades since those dense urban areas have been considered any sort of default desired social or cultural target for most Americans or American culture as a whole. It was different 70 years ago…