By 2050-2060, what will America look like demographically and socially/culturally?
Will it still be a superpower? What will the economy and standard of living be like?
America in 2050, roughly speaking, will be more divided, and more religious. And have a large elderly population. The population will be on the low side of 400 million. Security concerns will be prominent. Illiteracy and education will be national problems. Propaganda (both ideological and commercial) will be terrifyingly effective.
It will still claim to be a superpower, and will be good at bullying smaller nations without other near-peer protectors. It will no longer enjoy any sort of significant edge over near-peer competitors. Military and security, including mercenaries, law enforcement, and wealth protection will make up over 20% of the economy.
The economy will be dominated by favored players. Resource extraction will be back, as will some domestic manufacturing. Total GDP in absolute terms will have grown less than projected. The standard of living, measured by material goods, will average slightly higher, though there will be extreme disparities. Income inequality and class divisions will have continued to increase.