Protesters hold signs against President-elect Donald Trump in front of the White House on Nov. 9. (Nicholas Kamm/Agence France-Presse via Getty Images)

Democrats from President Obama on down are blaming their 2016 debacle in part on too much “identity politics” — messaging aimed not at voters broadly, but at Latinos, women, African Americans and the LGBT community as groups.

The one group Democrats did not target were their old mainstays, non-college-educated whites (especially the males of that species), who responded by giving Donald Trump a margin of 39 points over Hillary Clinton, while voters of color failed to vote for her in the expected numbers.

According to much newly minted conventional wisdom, Democrats can and should win back downscale whites by cranking up economic populism, without losing minorities, women and other key components of their coalition.

“We need to speak to their economic interests, that we get it, that we understand, that we talk about those things and we try to fight hard for those things,” said Rep. Tim Ryan (Ohio), who is challenging Rep. Nancy Pelosi of ultra-diverse San Francisco for leadership of House Democrats.

Easier said than done. Consider: Rust Belt states that Trump turned red — Ohio, Wisconsin, Pennsylvania, Michigan — heavily rely on coal for their electricity. Ohio and Pennsylvania also mine it. Some in those states likely backed the Republican partly out of opposition to Obama’s crackdown on coal, the Clean Power Plan, which Clinton supported.

Democrats could modify their climate change policy, in the name of protecting coal jobs and lower utility bills; good for the working class of all races. That would infuriate green voters — and donors — on the East and West coasts. It’ll never happen.

At a deeper level, Trump tapped unease among working-class whites that is related not to economics but to culture and race: in a word, identity.

A diverse society brings great benefits — social, cultural and economic. Urban Americans experience these daily. Life brims with new experiences, challenges, excitement, what an economist would call “positive externalities” of demographic change.

Yet homogeneity has benefits too. In rural areas, or small towns, where everyone speaks the same language, or practices the same customs, life can be simpler, more predictable, less frictional. Economists call these “compositional amenities,” and many people value them above the benefits of diversity — even above economic gains.

In a 2009 paper, a U.S.-British trio of social scientists led by David Card of the University of California at Berkeley used survey data from 21 countries to show that concern for compositional amenities is much more important in explaining public opinion on immigration than economic concerns, such as immigration’s impact on wages and taxes.

Anxiety about cultural change can, and often does, outweigh evidence on immigration’s economic impact — even positive data showing immigration actually raises wages overall, or that undocumented immigrants pay billions of dollars in taxes.

The study found that “compositional concerns” rise as educational attainment falls. As you acquire more skills and information, it becomes easier, presumably, to adapt to an increasingly diverse culture. And the converse also holds.

The analysis (previously reported by Thomas B. Edsall of the New York Times) was based on survey data from Europe over a decade ago. Still, the fact that the Card team’s findings applied across different societies on that continent suggests relevance to the United States, too — as does the fact that Trump just got himself elected president with overwhelming support from non-college-educated whites in smaller cities and rural counties by telling them he would build a wall on the Mexican border, impose “extreme vetting” on would-be immigrants and deport large numbers of the undocumented.

A General Motors plant in Lordstown, Ohio, would have closed but for Obama’s rescue of the auto industry; Trump won the surrounding county by six points.

The Democrats’ dilemma, then, is this: They can make only limited political gains with an economic pitch to the white working class, unless they adjust on immigration and other issues of identity too, probably.

Yet this would require compromising on what the party defined as matters of basic justice and tolerance, and turn off voters from their racially and ethnically diverse “coalition of the ascendant.”

Indeed, some on the left are already warning that conceding on identity politics would be a capitulation to “white supremacy,” in the words of Columbia law school professor Katherine Franke.

It’s an understandable impulse — no concessions to this demagogue. And Democrats may end up doubling down on identity politics because of it.

The question is whether this will prove effective, or prove to many whites that Democrats just don’t understand them, or care to; certainly Trump will encourage them to think so.

The alternative, of course, is to appeal to the public on the basis of our common American identity, and aspirations, rather than our overlapping grievances — cultural, racial, economic or otherwise.

For the time being, no leader or party shows any interest in that. The one that eventually does, though, might own the political future, if we still have one.

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