‘American politics has often been an arena for angry minds.” Not a comment on this year’s presidential campaign but an observation on another US presidential race, that of 1964. It is the opening line to one of the most influential political essays of the postwar era, The Paranoid Style in American Politics, first published 60 years ago this month.

The very title of Richard Hofstadter’s essay is redolent of contemporary fears. As Donald Trump has, over the past decade, built a movement out of anger and disaffection, old copies of Hofstadter have been dusted off and op-eds written with titles such as “The paranoid style in American politics is back” and “Donald Trump’s style perfectly embodies the theories of renowned historian”.

Not just Hofstadter’s analysis of the paranoid style but his evisceration of populism, too, has found a new generation of readers. Yet, as brilliant and influential as Hofstadter was, he was often wrong on both issues, and it is his wrongness that has shaped much subsequent debate.

One of America’s most celebrated historians, Hofstadter moved from Marxist leanings in the 1930s into a cold war liberal who regarded social consensus rather than class conflict as the defining feature of American history. His 1964 essay, an abridged version of a lecture he had given in Oxford (the full version appearing later in book form), was an attempt to confront a new, belligerent form of rightwing reactionary politics that had emerged, displayed in Joe McCarthy’s anti-communist witch-hunt, in the creation of the ultraconservative John Birch Society, and in the success of Arizona senator Barry Goldwater in routing the Republican establishment to secure the party’s 1964 presidential nomination.

The mainstream response to Goldwater in the 1960s prefigured in many ways the hostility to Trump half a century later. Some saw Goldwater’s rise as portending fascism. Fact magazine published a special edition on “The Mind of Barry Goldwater” in which more than 1,100 psychiatrists, none of whom had ever met the would-be president, diagnosed him as “psychologically unfit” for office. If he consolidated his Republican “party coup” by winning the election, Hofstadter warned, he would “put the democratic process in this country in jeopardy”. Goldwater lost to Lyndon Baines Johnson by a landslide.

For Hofstadter, the new right was a potent expression of the “paranoid style”, a way of thinking that cast conspiracy not as a singular occurrence, but as “the motive force” in history. “The paranoid spokesman”, Hofstadter wrote, “always speaks in apocalyptic terms”, and is “always manning the barricades of civilization” in the existential struggle between good and evil.

Hofstadter insisted he was not using “paranoia” in a clinical sense, but “borrowing a clinical term for other purposes”. Yet, he also believed “the recurrence of the paranoid style” across history “suggests that a mentality disposed to see the world in the paranoid’s way may always be present in some considerable minority of the population”. In other words, it is an ineradicable pathology lying latent within the population, and activated by the emergence of particular social movements or political organisations.

It is an argument that many find appealing because it gives licence to dismiss alternative viewpoints as a form of mental illness. It is also a perspective that wrenches political responses out of a historical frame. Even “millennial sects of Europe from the eleventh to the sixteenth century”, Hofstadter wrote, exhibited a “psychological complex that closely resembles” that of the reactionary right in postwar America. “The paranoid style as described by Hofstadter,” the historian Andrew McKenzie-McHarg wryly observes, “is present throughout history yet does not itself appear to have any real history of which to speak.” It is a perspective, too, that allows liberals to be oblivious to the presence of such traits within their own ranks. Rightwing populists certainly trade heavily on conspiracy theories, whether about immigration or the elites. Liberal panics about the coming of “fascism” and the “end of democracy” often exhibit, though, an equally apocalyptic view and present the fight against populism in black and white terms.

This takes us to the second key theme in Hofstadter’s work in the 1950s and 60s – his critique of populism. As Hofstadter moved from early radicalism to midlife centrism, he became increasingly wary of the masses and their impact on culture and intellectual life. His growing distrust of working-class movements led him to be sceptical of democracy itself. “Intellect,” he wrote in his 1963 book Anti-intellectualism in American Life, “is pitted against democracy, since intellect is felt to be a form of distinction that defies egalitarianism.”

This political transformation shaped his reading of history. Until Hofstadter, most historians had viewed the rise of Populist movements in 1890s America in positive terms. These original populists were driven by a hatred of the inequalities and injustices of the so-called Gilded Age. They sought to forge cross-racial coalitions of farmers and workers to demand democratic reforms, progressive taxation and government ownership of utilities.

Hofstadter, in his 1955 book The Age of Reform, questioned this narrative, portraying the movement as a racist insurgency with a conspiratorial view of the world that “seems very strongly to foreshadow” McCarthyism and postwar reactionary conservatism. Strands of bigotry were certainly on display, especially as the movement disintegrated in the face of a ferocious assault from the established order. But the Populists’ democratic and egalitarian promise cannot be gainsaid.

A host of historians, including C Vann Woodward, Lawrence Goodwyn and Walter Nugent, challenged and largely rebutted Hofstadter’s revisionism. The political substance of his argument, however, became entrenched. After Hofstadter, Nugent wrote in a 2013 preface to his 1963 book The Tolerant Populists, “populism” began “to carry the connotation of demagogic, unreasoning, narrow-minded, conspiratorial, fearful attitudes toward society and politics”. It still does, shaping our view not just of the past but of the present, too.

“Having come of age in a political culture that glorified ‘the people’ as the wellspring of democracy and decency in American life,” Eric Foner, perhaps the most distinguished living historian of the American tradition, observed of his mentor’s trajectory, “he came to portray politics as a realm of fears, symbols and nostalgia, and ordinary Americans as beset by bigotry, xenophobia and paranoid delusions”.

The loss of hope, the sense of betrayal, disillusionment with fellow Americans – that might describe not just Hofstadter’s trajectory but America’s too. The tragedy is that whoever wins on Tuesday, that will not change.