As people were trying to make sense of the Trump phenomenon earlier this year, a number of journalists noted the usefulness of the "Middle American Radical" (MAR) concept. This term was first popularized by Donald Warren's 1976 book, The Radical Center, though the phrase is now probably more commonly associated with the late paleoconservative writer Sam Francis.
The Radical Center is indeed a good book and very relevant to the 2016 presidential election. Unfortunately, it is also very hard to track down, especially if you do not have a university affiliation that gives you access to interlibrary loans.
Anyway, as a service for those not familiar with the book, I am going to just leave some short passages from it, in the hope that it gets more citations in the future:
But there is evidence that a second group drawn from similar social strata exists. A more militant, more aggressively dissatisfied segment of Middle America gave Wallace strong support in the presidential primary period of 1972. In the presidential election of that year, with Wallace eliminated many of the Middle Americans stayed home. Still others who retained their original allegiance to George Wallace voted for Richard Nixon. It was not with deep commitment but out of a restricted choice that many took such a course of action. There were other signs of hostility and frustration as well. Middle American support of Spiro Agnew’s attacks on the media prior and during the campaign of 1972 and the construction worker attacks on peace demonstrators in Manhattan a few years earlier, all form the background for what we are describing. The litany goes on. The truckers’ protest in the 1974 “energy crisis” posed basic challenges to the neat political stereotypes which we academics often ask people to live up to. Protests over textbooks that are offensive to parents in West Virginia, as well as the bitter disputes surrounding desegregation of schools in Boston, serve as more recent manifestations. The organized manifestation of these recent confrontation is the ROAR group (Restore Our Alienated Rights).[xv-xv1]
So it is with Middle American Radicals: siding first with the traditional left in opposition to the privileges and power of the rich corporations … and yet mouthing the shibboleths of the far right in its fear of the growing power of the poor and minority groups in our society. [xxi]
The rich give in to the demands of the poor, and middle income people have to pay the bill. 
McGovern, with his following of the poor, affluent liberals, college students, blacks, chicanos and anti-war dissidents, was the epitome of what the MAR resented on the American political scene. 
[I]t is clear that the absolute level of earning differences between MARs, blacks, and other groups is not the most fundamental issue. It is, rather, in the context of particular status concerns that the MAR ideology flourishes most. Consequently we must be particularly attuned to the perceived status rankings of various kinds of federal, state, and local programs. For example, U-235 housing becomes an important way by which Low Income and minority groups are able to move into better housing. But efforts must be made to allow for the kinds of status differentiations which avoid having persons with identical homes living next to each other, or in the same neighborhood, when one of those individuals is paying half the rent of the other. MARs are not against blacks having good housing, but they are concerned in terms of identifying those who had gone the conventional route and those who were being subsidized.
Clearly it is now fashionable to recognize that many Americans are distrustful and out of touch with their elected officials. And yet the most recent findings about the outlook of the MAR provides a sharp outline of just how endemic such a perspective has become. No democracy can tolerate that kind of dissatisfaction and not stumble into great danger. For a while MARs may indeed be subdued and less able to carry out via a party, a program or a leader what is implied in their anger and dismay with the course they see American society following. But unless bridges are formed and policy adjustments are made, the MAR perspective may grow to the point where it begins to pervade society and affect the political and social fabric with possibly drastic consequences.
There is much more that I have to say about this book, and the cultural group it discusses, but that can wait for another day.