I think there is a lot of truth to the idea that, for one group of Americans, the world is changing too fast; while to another group it is not changing fast enough. This issue was exacerbated by how America came out of WWII relatively unscathed -- the war was not fought here and we had no major rebuilding to do. Instead, we were helping the rest of the world get back on their feet, with the advantages of the jobs that created and the world's largest economy.
Of course, the rest of the world started catching up, after a couple of decades -- not helped by some of the decisions made by the WWII generation while they were on top. Additionally, with the advent of various technologies, to include electricity and various types of machinery (industrial, construction, transportation, computational, etc.), the world became smaller and the pace of technological innovations increased exponentially. The world was changing to a large degree.
Attitudes also started changing; from the wartime attitude where the nation and communities came first to the ideals of things like "rugged individualism" -- to oversimplify, as one movie put it, "Greed is Good." This includes the ideas of Ayn Rand becoming popularized, where if people just act in their own best interests to make themselves happy, it will help everyone in society to become "more."
OTOH, there were groups in America being left behind (such as Blacks and Native Americans), particularly with Jim Crow laws still existing. So, as the rest of America started getting more prosperous, it upset groups that were being left behind. They started demanding that they be included, that they be allowed an equal place in America.
Of course, as things for Blacks improved, things for "small town America" tended to get worse. As America prospered, and with the idea that making corporations more prosperous would help the nation, manufacturing jobs started leaving the nation to areas of the world where labor was cheaper. Family farms were becoming less and less profitable, as they more often had to compete with large corporate farms, and small town American shrank as they no longer had the jobs.
As such, many Americans feel as if they are being left behind. The towns they live in are dying, the homes they counted on as an "investment" are losing value, while for people in cities housing prices are skyrocketing, so working people can't afford housing where they can get jobs. This is exacerbated by, with the skyrocketing housing prices, wealthier people buying real estate as an investment -- raising prices and often removing housing from the market.
So you have some Americans who find the rate of change too fast. Computers, as useful as they are, scare many -- particularly with the various scams. Many Americans lifestyles are threatened by their towns dying off, often needing to move to find a decent paying job, etc. Other Americans are chasing jobs to find "success" but are finding that, even with a good job, they tend to be priced out of decent housing -- particularly if they want "the American Dream" of owning their traditional "white picket fence" style home. Last, many Blacks still feel left behind -- despite how things have improved over the last couple of generations -- and other minority groups look at what Blacks have achieved (in terms of civil rights, such as gays) and want protections to live their lives openly and to pursue their version of happiness. Not to mention, the idea of greed becoming "good" and feeling like they are falling behind "the Joneses" (the stereotypical next door neighbor who gets new cars and new leisure "toys", like boats and RVs, that the ones being left behind can no longer afford).
Thus, we've ended up with various groups -- groups that feel they are being left behind, whether small town America or traditionally persecuted minorities; groups that feel the world is changing "too fast," to include that the moral standards they grew up with are quickly changing; etc. And, of course, there are those who see the excesses of the past have become and are becoming even bigger issues in the future -- whether it be greed (particularly corporate greed)
And into this, we drop American politics, where it seems like many politicians care more about fanning the flames of anger of those that feel the world is "abusing" them (in the ways it is changing), doing it to promote their own political power while doing little that actually improves the lives of those they are allegedly "helping." This typically not only includes empathizing with people's anger but telling them who is to blame for their issues. This can lead to illegal behavior -- behavior they may not see as "wrong" -- whether it be to break into the Capitol building to "make their voice heard" or shoplifting, even openly looting stores to get what "they deserve" for the wrongs that have been done to them.
Admittedly, this is somewhat oversimplified and I'm sure I'm missing some pieces, but the fact remains that it is largely people feeling they are being left behind and being somehow "cheated" of the life they "deserve" -- whether that be to live in an old-fashioned small town or even a friendly neighborhood where you can leave doors unlocked all the time, or whether it is getting paid what they believe is a fair wage where they make enough for housing, food, and plenty of disposable income for toys and vacations. What we seem to get sold by politicians is the idea that is "others" are to blame and they need to be stopped -- without any real ideas about how to improve the nation.
