Evidently, income inequality has gone up in the U.S. substantially in the last couple of decades. Although both rich and poor have increased their incomes, the rich have increased theirs by a greater fractional amount. Our social mores may simply reflect the greater economic equality of a generation back, and will eventually shift. I would be very sorry if this turns out to be so.
I understand that economic mobility is still pretty high -- that is, a given person has a good chance of moving around quite a bit in the income distribution over a lifetime. This fact (and the fact that lots of people believe this) may be more important than actual income figures.
It is also the case that even lower-income Americans have a standard of living that is pretty good by global standards. This means that the differences between richer and poorer are not so much qualitative as quantitative. Richer people drive better cars, listen to better stereos, and go to better colleges -- but both rich and poor drive cars, listen to stereos, and have some access to higher education. When my Mom worked at a small-town bank in Arkansas, I can remember listening to some of young bank tellers talk about going on a cruise for vacation. They weren't making a lot of money, but they could save enough to go on a cruise. Rich people went on nicer, longer cruises to better places, but Arkansas bank tellers were getting the "Wal-Mart" version of the same experience. (I thought, heck, I was pretty well off compared to those tellers and I'd never been on a cruise. I'm better off now and still haven't.)
Finally, it seems to me that we have a lot of different heirarchies in this country, and they do not agree. Different sorts of people rise to the top of the political, economic, media and academic worlds, just to pick out a few. This means that, despite everything, we do not just have a single "upper class" in this country. Since there is no single way to define "up" and "down", it is harder for society to feel stratified.
These are, as my friend Mike would say, "epsilon-baked" ideas. I am not an economist or a sociologist and have no real desire to be one. But what the heck, it's a blog. Comments welcome.