Donald Trump's victory in GOP primaries caught most people by surprise -- go back and look at what the pundits were saying about his candidacy last summer. As I've worked to make sense of it, I've found many books to be quite useful. To make sense of why Trump was able to pull it off, despite the furious protests of the conservative movement, the following books would be a good place to start.
In my estimation, Donald Warren's book The Radical Center is the best place to start if you want to understand Trump's constituency. Although it is now rather dated (1976), it's insights are just as applicable today. The book is unfortunately hard to track down; I got my copy via interlibrary loan. Warren's basic argument is that there is a large, and mostly unrepresented, demographic in America, which he dubs the Middle American Radical (MAR). These are people who are not really poor, but not wealthy either. Their economic status is precarious, but they are not really counted as a victim group. This is a group that had once been solidly Democratic, but turned on the Democrats in the 1960s and 1970s because it began to feel that the Democrats did not really care about their interests. But they also never really became strong Republicans, even if they did vote for Nixon.
During the 60s and 70s, leaders of groups that had long supported the Democratic Party, such as labor unions, were shocked to find that large number of their members were planning to vote for Wallace or Nixon. Voters who had previously been drawn to the party of economic fairness and equality were more inclined to support the party of “law and order.” As the Democratic Party’s focus shifted largely to issues of racial equality, whites in the economic middle and lower middle classes shifted allegiances. Yet they did not really become conservatives, at least not on economic issues. Warren noted the problems this posed for those who wanted to make sense of this group, as MARs are inclined toward oversimplification of economic issues and often hold contradictory opinions: “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.”
The next book on the same subject I recommend is Sam Francis' work, Revolution from the Middle. Whereas Warren was concerned by the MAR population and its alienation, Francis (who was a paleoconservative) thought this group was the best candidate for destroying the duopoly enjoyed by the GOP and the Democrats, a duopoly he hated. He hoped that Pat Buchanan would lead a succesful Middle American Revolution. Those hopes were not realized, but Trump is largely following Buchanan's playbook, and having more success.
Kevin Philips' largely forgotten book, Post-Conservative America, also has some useful things to say about what the MAR could mean for the Republican coalition.
To understand why a candidate deliberately seeking to activate middle American anxieties is having much more success today than in the 1990s, we have to understand the demographic and economic changes at play. The best book for making sense of how demographic changes influence politics, I recommend White Backlash by Marisa Abrajano Zoltan Hajnal (I reviewed that book here). This book makes the case, using an impressive variety of data, that a larger immigrant population makes non-Hispanic whites more anti-immigrant. I made a similar argument in my own book, White Voters in 21st Century America.
To understand the economic changes leading to greater levels of economic anxiety in the American middle class, and hence greater resistance to globalization, there are more books than I care to list here. But one of my favorites is Average is Over by Tyler Cowen. This book generally argued that the large middle class that rich countries have enjoyed for many decades is going to disappear, largely due to technological changes that will make many good jobs obsolete. We will be left with a wealthy upper class, dominated by those needed to keep the economy running, and a giant mass of largely superfluous people (superfluous from an economic standpoint).
Bryan Caplan's book, The Myth of the Rational Voter, made a strong case that most Americans exhibit an anti-market and an anti-foreigner bias. Trump is clearly tapping into both of those sentiments.
As for the conservative movement and its ineffectual response to Trump, there are a few resources I recommend. Although he did not argue (as I do) that conservatism is now too intellectually and ideologically rigid to respond to a rapidly changing America, that was one of my takeaways from Michael Lee's book, Creating Conservatism. I discuss this book in greater detail here.
I hope I will be forgiven for including my own book, Right-Wing Critics of American Conservatism, as a useful resource for understanding conservatism's waning power.
As a response to the claim that Donald Trump is somehow a fascist (a claim I think is mistaken), it is useful to have a better understanding of what fascism actually is. My favorite scholarship on this subject is by Roger Griffin. I especially recommend his book, Modernism and Fascism. To learn the history of how the word fascism has been used in political rhetoric, I recommend Paul Gottfried's book, Fascism: The Career of a Concept.
Of course, Trump's success is not just the result of impersonal social forces. Much of it can be explained by the man himself. I've now read most of his books, but the most useful starting place is his best-known work, The Art of the Deal. The most remarkable thing about this book is that he very clearly explains his strategy for dealing with media. He made no secret that he strategically employs hyperbole and personal attacks. Yet despite advertising his strategy far in advance, no one has been able to develop an effective response.
These are just my initial thoughts on this subject. I will surely add to this list in the months ahead. I welcome any additional suggestions.