"About to?" It already is brutal for the bottom half. And the 90th percentile is too low: people in that range are paupers by comparison even to the top 5. I think the 95th to the 99th percentile is the region to look at. There are some seriously deluded individuals in that group who think they won't be on the outside with the rest of us when the top pull the gates closed behind them.
America is a nation of temporarily inconvenienced millionaires. This disconnect between expectations and reality is one of it's biggest problems. You can visit any number of poorer nations where being poor does is not a punishment, it not equate to a difficult or miserable life, because society, it's services and it's infrastructure are all built to accomodate people of modest means. In America is designed for you to have a McMansion with a two car garage, and if you can't meet the bottom line you either go into debt to pretend you're meeting it or you're cast to the fringes where you struggle just to survive in a world that is not designed to accomodate People of modest means.
The (disputed) John Steinbeck quote you might be referring to: "Socialism never took root in America because the poor see themselves not as an exploited proletariat, but as temporarily embarrassed millionaires"