That the income distribution is shrinking in the middle distribution of the population of the U.S. is a critical data trend with a number of unpleasant implications.
From an ideological perspective, it damages the traditional worship of hard work and the idealization of middle class life. Idealistic visions (as reflected from the movies, the shows, the social policy of the era around the middle of the 20th century pretty much up until the end of it) showed the suburban life, the housewife, the house, the two car garage. It's easy to be politically complacent, knowing you're in the country that's number one, when those things are what you can realistically strive for. Laissez-faire capitalism was always sold as being more fair than the evil 'socialist' Europe - and worse - that was further east. Because even when you were low, you could feel comfortable about bettering your lot ("my grandfather came here with nothing..."). Now the stats are pointing away from that reality.
Economically it's pretty iffy, given that 80+% of the American GDP is the services sector, which has a large component of dependency on spending power. Retail alone is what, 5-6% of GDP, and then you have entertainment, real estate, and much else that depends on money being spent by people not on the very top.
Real estate's an interesting one. Another piece of the Dream that made us the greatest country, as we were told. That's another trend that the current generation faces that was not faced in the 1950's: the ratio of median income to median housing costs.
A lot of us here are in IT (or Law or other professions that I have noticed), and in many ways we're very lucky, even if we did work hard to get to where we are, since we're further up the curve and don't face the same exposure. In the U.S. health care costs and educational costs have also gone up well above the income increases, adding further to the discontentment.
Meanwhile, the political world has gone mad. We're now back to identity politics, with demagogues on both sides of the spectrum. Any explanation about the economic underlying conditions? Nope, instead we talk about immigrants, or X racial privilege, or gender/racial identity in the boardrooms, or X foreign power.
New thread suggestion: "Ask HN: Which remote island can I escape to and live comfortably and cheaply?"