[natechols]

> What I think will happen will be extreme concentration of wealth in a few places, and those will put up sky-high walls (literal and figurative) to block out everyone else.

That accurately describes the USA today (and has for many decades), and especially some of the wealthier parts like the SF Bay area.

[caskstrength]

USA has a long way to go yet. Think attack dogs, minefields and being shot in the back from watchtower for trying to illegally cross the border Berlin wall-style.