I've made this point a number of times but I still feel it's poorly understood. The excellent Sheri Berman has a terrific article up on the Post's Monkey Cage blog where she makes this argument about as lucidly as it can be made.
"Many people blame increasing racism and anti-immigrant sentiment for the rise of radical populism. Given populists’ racist and xenophobic pronouncements, this view is not surprising. However, it rests on shaky empirical foundations and a flawed understanding of the relationship between political preferences and political outcomes.
To better understand the sources of populism, it’s helpful to remember that people have views about countless political topics — but only some are directly relevant to their voting. To make this clear, political scientists differentiate between preferences and salience. Preferences refer to a person’s view on an issue, while salience refers to the intensity or importance attached to that view. Individuals have many political preferences, but only those that are salient decisively influence political behavior.
The story of populism’s current successes is not a story about how people are becoming more racist, or more anti-immigrant. Instead, it is a story about how some people’s preexisting racial or social anxieties have become more salient, because of right-wing and left-wing politicians....
Scholars consistently find a strong connection between populist success and the salience of race, immigration and national identity. This is not primarily because focusing on them changes voters’ views, but rather because it causes voters already predisposed to be anxious about these issues to vote on the basis of these anxieties. As Larry Bartels notes: “There is no clear relationship between levels of populist sentiment and actual support for right-wing populist parties … Where populist entrepreneurs have succeeded, they have done so by tapping a reservoir of populist sentiment that existed all along.”
This is why populist right-wing politicians in Europe focus on these issues, demonizing immigrants and minorities, and blaming them for rising crime rates, eroding national values and so on....
However, it isn’t only populists who have made immigration and national identity more salient. As Maria Snegovaya and I argue in a recent article, the left has played a role as well. During the postwar period, political competition, particularly in Europe, pivoted primarily around economic policy differences. But by the late 20th century, economic differences between left and right diminished as the former accepted much of the neoliberal agenda. In Europe, as the left and the right converged economically, politicians tended to focus more on sociocultural issues “so as to be able to display meaningful programmatic differences.” With fewer economic differences between left and right, voters had reason to pay more attention to noneconomic factors as well. In the United States, Sides, Tesler and Vavreck found that along with Donald Trump’s pivot, Hillary Clinton focused more on race and immigration than Barack Obama. The 2016 campaign was thus particularly focused on these issues and the candidates particularly divided on them, raising their salience and thus their effect at the ballot box."
The point about the how the left's approach has played into the populist moment is key. Berman concludes that the left, with a different playbook, actually has a reasonable chance of turning things around. I agree.
"The increasing salience of immigration and national identity, rather than growing racist and anti-immigrant sentiment, is crucial in explaining populism’s success. That changes in salience have mattered more than changes in preferences means that populists’ political success may be less enduring than it seems at first. This is most obviously true because racism and xenophobia have declined over time. It may also be true because while predispositions toward racism and xenophobia can be deep-seated and hard to change, the salience of racial, status and other anxieties can be influenced by political actors. This suggests that populists’ political opponents may enjoy greater success in the future, if they sideline the issues on which populism thrives."