However often President Trump strays from his favored political strategy, he faithfully returns to it like a dog to a bone: first, polarize the American electorate along racial, cultural and economic lines, then exploit the schisms that have supplanted the class divisions that were once central to both American and European partisan politics.

On one side of the divide are those whom the political scientists Pippa Norris and Ronald Inglehart describe in a 2016 paper as comfortable with “an inexorable cultural escalator moving postindustrial societies steadily in a more progressive direction.” This new direction amounts to what the authors call

an intergenerational shift toward post-materialist values, such as cosmopolitanism and multiculturalism, generating rising support for left-libertarian parties such as the Greens and other progressive movements advocating environmental protection, human rights, and gender equality.

On the other side, Norris and Inglehart write, is a counterrevolution, a

retro backlash, especially among the older generation, white men, and less educated sectors, who sense decline and actively reject the rising tide of progressive values, resent the displacement of familiar traditional norms, and provide a pool of supporters potentially vulnerable to populist appeals.

Economic distress, they argue, reinforces cultural alienation to produce fertile terrain for Trump. “Fears of economic insecurity, including the individual experience of the loss of secure, well-paid blue-collar jobs, and the collective experience of living in declining communities of the left-behinds” combine to make voters

more susceptible to the anti-establishment appeals of authoritarian-populist actors, offering simple slogans blaming “Them” for stripping prosperity, job opportunities, and public services from “Us.”

The collision of these forces has produced the emergence of an American authoritarianism. In their book, “Cultural Backlash: Trump, Brexit and Authoritarian Populism,” which comes out later this week, Norris and Inglehart write that Trump has assumed leadership of this authoritarian movement,

defined as a cluster of values prioritizing collective security for the group at the expense of liberal autonomy for the individual. Authoritarian values prioritize three core components: 1) the importance of security against risks of instability and disorder (foreigners stealing our jobs, immigrants attacking our women, terrorists threatening our safety); 2) the value of group conformity to preserve conventional traditions and to guard our way of life (defending “Us” against threats to “European values”); and 3) the need for loyal obedience toward strong leaders who protect the group and its customs (“I alone can fix it," “Believe me,” “Are you on my team?").

The United States and many European countries, at various points in the last decade, have reached a critical juncture, Norris and Inglehart write: “The interwar generation, non-college graduates, the working class, white Europeans, the more religious, men and residents of rural communities” have come to feel “estranged from the silent revolution in social and moral values, left behind by cultural tides that they deeply reject.” These men and women, “until recently the politically and socially dominant group in Western cultures,” reached

a tipping point at which their hegemonic status, power and privilege is fading. Their values make them potential supporters for parties and leaders promising to restore national sovereignty (Make America Great Again), restrict immigration and multicultural diversity (Build a Wall) and defend traditional religious and conventional moral values.

The debate over whether the rise of right-wing populism is driven by cultural anxiety, racism, ethnocentricity or economic deprivation may “be somewhat artificial,” Norris and Inglehart contend because

interactive processes may possibly link these factors, if structural changes in the work force and social trends in globalized markets heighten economic insecurity, and if this, in turn, stimulates a negative backlash among traditionalists toward cultural shifts. It may not be an either/or question, but one of relative emphasis with interactive effects.

In this country, the nominally class-based politics of the New Deal fractured when working class non-college whites felt abandoned by a Democratic Party that shed its pre-civil rights, segregationist southern wing and that by the 1970s had adopted a culturally and racially liberal agenda. Over the past five decades, these white voters have formed the core of the populist right. Conversely, minorities, many of whom face the same economic hardships as working class whites, if not worse, are firmly aligned with the party of social and cultural liberalism and racial equality, the Democratic Party.

“The new cultural cleavage dividing Populists and Cosmopolitan Liberals,” Norris and Inglehart write, is “orthogonal to the classic economic class cleavage” — in other words, the new division cuts across and splits the old economic class solidarity.

Data from a preliminary American National Election Studies survey — provided to me by Matthew DeBell, a scholar at Stanford’s Institute for Research in the Social Sciences — revealed the strength of this new cleavage. The survey asked 2,500 men and women to rank their feelings toward Trump on a “feeling thermometer” scale of zero, “very cold or unfavorable,” to 100, “very warm or favorable.”