The wealthiest one out of 1,000 US families -- the 0.1 percent -- comprise about 115,000 households whose net worth starts at $20M, and goes up and up from there, accounting for at least as much wealth as the poorest 90 percent of US households.
Mere 1 percenters are often people who got lucky doing real work: movie stars, doctors, lawyers, engineers, accountants, etc. They own nice houses and have retirement savings, but they don't own islands, helicopters, or gilded survival shelters that they plan to hide in while the rest of us eat each other on the blighted, apocalyptic surface-world.
Because they tend to earn their money from work, it is taxed at something like a normal rate; in contrast, the 0.1 percent earn nearly everything from capital gains, which not only enjoy much lower tax rates (because US tax policy rewards owning things ahead of doing things) and is much easier to shift offshore.
The 0.1 percent has a few tech billionaires and a few more finance people (naturally) -- but the fastest-growing cohort in that exalted tier is professional descendants, who inherited their wealth from their forebears, with names like "Walton" and "Koch."
One percenters are more likely to see their natural allies as everyone else because they live in precarious circumstances and have a lot to lose.