How can we explain the surprising electoral success of Donald Trump, especially in light of his lack of political experience, limited knowledge of and specificity about policy issues, and crude and insulting rhetoric? Who supports him and why do they find the business tycoon to be so attractive?

Analysts have identified four major features of Trump supporters. First, few of them have graduated from college. This is an important statistic because it likely speaks to their economic frustrations. Consider that only 68 percent of men without a bachelor’s degree had a full-time job in 2013. Moreover, the wages of these men, adjusted for inflation, have declined significantly since 1990. The shift of many manufacturing jobs to other countries and the low salaries of service jobs in the United States have reduced the employment opportunities and income of men and women who have not completed a college degree. Consequently, many of these people are disgruntled and ripe for change — and many are supporting Trump.

Second, Trump’s supporters are individuals who complain that they have little political voice. In polls, high percentages of those who agree with the statement “people like me don’t have any say about what the government does” prefer Trump. People’s conviction that they lack power and influence predicts Trump support much better than any other factor including amount of education, income, age, race, or attitudes toward Muslims or illegal immigrants.

Trump has promised to help these despondent, largely white Americans increase their political clout and financial prospects. He touts his business success and claims that when he becomes president America will regain its world influence and winning ways. Trump’s promises to “Make America Great Again” and to restore the power, prestige, and privileges of whites especially appeal to people who feel excluded from the political process.

Third, Trump’s backers are willing to trade greater security for less liberty. They want the government to protect them from threatening “outsiders” whether they are terrorists, refugees, or illegal immigrants. They complain that many immigrants are not playing by the nation’s rules and are taking advantage of hard-working white Americans. Trump has sought to alleviate the fears of these individuals by pledging to construct a towering wall between the United States and Mexico, promising to keep Muslims refugees out of America, and calling for the deportation of most illegal immigrants.

Deeply alarmed by the proliferation of terrorist attacks around the world, Trump supporters protest that President Barack Obama’s policies are not keeping the nation safe. They applaud Trump’s plans to create a database of Muslim Americans, increase surveillance of mosques, and temporarily ban Muslims from entering the United States.

Fourth, Trump supporters disproportionately reside in sections of the United States where racial resentment is high. These white men and women, who often refer to themselves as the “silent majority,” fear that minorities and immigrants are advancing at their expense and want to turn the clock back to a time when America was not so culturally diverse and their lives were less complicated. They do not trust Obama, accuse him of intensifying racial tensions, and argue that they suffer from reverse discrimination.

Two books written to analyze Adolf Hitler’s rise to power — Erich Fromm’s “Escape from Freedom” (1941) and Eric Hoffer’s “True Believers” (1951) — help explain why many Americans find Trump appealing. Fromm, a German psychologist who moved to the United States in 1934, analyzed how Nazism became widely accepted in society where people enjoyed substantial freedom and high levels of education. Fromm contended that the psychological conditions in Germany caused by the nation’s unexpected defeat in World War I and the punitive Versailles Treaty led millions to want Germany to restore its power and regain the world’s respect. This desire, coupled with the economic impact of the Great Depression, made many discontented, insecure, and despondent Germans receptive to the message of an authoritarian leader who vowed to make Germany great again.

The core of Fromm’s argument is that in times of rapid social change, economic stagnation, and rampant anxiety, people often find freedom to be frightening. Freedom causes people to feel adrift, unsettled, bewildered, isolated, and fearful. Terrorist threats, reduced purchasing power, bleak economic prospects, lack of respect, perceived unfairness, and declining moral standards lead many to struggle with freedom. They are unsure about how to best use their freedom; making decisions is daunting and anxiety-provoking. To relieve this anxiety, some seek to “escape from freedom” by identifying with and listening to strong leaders who explain how the world actually works, tell them what to do, and promise to improve their lives. This relieves them of personal responsibility and gives them the comfort and certainty they crave.

Hoffer, an American longshoreman and social philosopher, argued in “True Believers” that individuals who are experiencing these pressures and adopt this mindset are inclined to join mass movements that guarantee to change the world and improve their circumstances. Such individuals are attracted to movements and leaders that gives their lives purpose and direction, help them feel better about themselves and their prospects, and enable them to subsume their individual lives in a larger entity.

Hoffer also contended that “true believers” often shift from one social movement to another because they are more concerned with the psychological benefits their participation brings by identifying with a powerful, magnetic leader than with the movement’s actual ideology. He maintained that various nationalist and social movements, whether on the left or the right, typically attract the same kind of adherents and use the same rhetoric and tactics.

I am not arguing that Trump should be compared with Hitler, only that the some of the conditions that existed in the 1930s that led Germans to support Hitler exist in America today and prompt people to back Trump. These prescient books help explain why Trump’s mystique seems to be tarnished so little by his vulgar and outlandish behavior and why his momentum seems so difficult to halt despite the concerted efforts of many Republican leaders.