In 2016, 2020, and 2024 Donald Trump and other Republicans won record numbers of votes from non-Hispanic white voters without a college degree. This shift is particularly important given the concentration of these voters in what Stephanie Ternullo refers to as the “Heartland”—those crucial swing states in the Midwest that our Electoral College has christened as must-wins for candidates seeking the White House. Implicit in this narrative, and explicit in Ternullo’s theory, is a model of partisan change rooted in social groups. Voters assess the social groups that make up each political party, determine where they fit in with or how they feel about those social groups, and update their partisanship or voting behavior accordingly. While this model of partisanship and partisan change is well-established—see, for example, Donald Green, Bradley Palmquist, and Eric Schickler’s 2002 book, Partisan Hearts and Minds—the extant literature has little to say about how Americans observe, process, and interpret these fairly abstract and distant trends. It is generally assumed that, in an era of nationalizing politics, shifting perceptions of partisan social groups will play out similarly across the U.S. Indeed, pundits generally interpret and report political shifts in the aggregate and at the national level. There may be talk of regional diversity—differences between the South, the Sunbelt, and the West are often highlighted—but the important trends are presumed to be national.

In How the Heartland Went Red, Ternullo intervenes in this debate to argue that these national-level aggregate trends are both “correct and incomplete” (p. 10) in that they leave out the important role that local institutions play in moderating national trends. Americans do not interpret politics exclusively through their screens while viewing, listening to, or reading about national news; they are embedded within local communities that are made up of different peers, institutions, economies, and cultures, all shaped by path-dependent local historical processes. Ternullo’s engaging, well-crafted, and thought-provoking book, therefore, attempts to identify and explain how these local-level differences slow down or speed up national political change. More specifically, what role do churches, non-profits, and unions play in moderating national political trends? How do these local institutions shape local culture as well as perceptions of political problems and solutions? And most importantly, which identities will be most salient when residents of these communities engage in politics?

To answer these questions, Ternullo draws on hundreds of interviews, historical case studies, government statistics, and media data collected in three predominantly White Midwestern cities that were all once part of the New Deal coalition but have experienced drastically different political trajectories. And she shows how national politics is refracted through diverse local institutions and thus differentially slows or speeds up the region’s shift to the political right.

The pseudonymous Motorville, for example, is one of a few remaining predominantly White New Deal counties in the U.S. that is still majority Democratic—an outcome that Ternullo attributes to politically active unions that have assisted in keeping local politics framed in economic and class-based terms. Local narratives suggest that the root causes of contemporary community ills can be traced to broader issues of structural inequality, which state and federal governments are uniquely situated to remedy. For Motorville residents, their class-based political identities appear to be most salient when thinking about politics, which has helped forestall the shift to the right that most of their peer communities have experienced.

Lutherton, however, abandoned the New Deal coalition and began voting more Republican by the mid-1950s in reaction to the burgeoning Civil Rights Movement. In contrast to Motorville, Lutherton’s local social institutional infrastructure is predominantly made up of churches and non-profits, which differentially diagnose community issues and their solutions as uniquely local. Solving community ills for Luthertonians is the purview of volunteers and churches, not the government, and white Christian social identities seem to be most salient both socially and politically.

Gravesend, in contrast to both Motorville and Lutherton, lacks a stable institutional structure to help diagnose local problems, identify feasible solutions, or establish durable community identities that could serve to moderate national trends. Communities like Gravesend have remained relatively politically divided from the 1950s to 2016, when they appeared to swing hard to the right in response to Donald Trump’s candidacy. Ternullo argues that this drive to the right was fueled to a large extent by a fear of immigrants of socialism, and of the perceived disappearance of their predominantly white, small-town way of life.

Ternullo’s ethnographic approach allows for rich theory building—and indeed a book that is far more enjoyable to read than most in political behavior. I suspect that this book will generate an enormous amount of discussion, debate, and scholarship about the nationalization of politics and the role of place in American political behavior. Nevertheless, How the Heartland Went Red raised several questions that, as a quantitative scholar of political behavior, I wanted to investigate more thoroughly.

The first has to do with a temporal mismatch between the nearly century of political change described in the book and the snapshot of data collected to understand this change. Ternullo adeptly identifies important historical political processes that transformed white communities around the U.S. during the latter half of the 20th century, including backlash to the Civil Rights Movement, post-industrial decline, and the collapse of organized labor, among others that are nicely summarized in Chapter 2. Yet the bulk of the evidence for the book’s theory and its mechanisms comes from contemporary ethnographic work with citizens in these communities and discussions about institutions, diagnostic frames, and identities in each. It is hard to understand long-term partisan change as a result of local institutional factors by examining the contemporary role and structure of institutions. The issue is that the local institutions identified as the nexus of political change—i.e., unions, churches, and nonprofits—could themselves be the product of other processes that generate both the institutions and the political differences. In other words, could local place-based institutions be a product of a confounder rather than a moderator of national political trends?

For example, if Motorville’s white Democrats largely avoided the racial backlash that pushed other communities, like Lutherton, to the right, the local-level Democratic elite could have continued to protect and politicize unions and embrace multiracial democracy to the present day. Similarly, white Democrats in Lutherton that fled the Democratic Party in the wake of the Civil Rights Movement and became Republicans could have invested heavily in maintaining strong local-level politicized Christian institutions and identities. In this alternate story, the contemporary political differences between Motorville and Lutherton could simply be explained by varying levels of racial resentment among white residents in both cities. The institutions, narratives, and identities identified as the reason for these political differences are simply themselves an outcome of these political changes.

This raises the question of other potential stories that could explain these political changes. I wonder what role demographic change might have played in these shifts. Racial threat, fueled by nonwhite migration to a community, could shape local partisanship among white residents or even drive racially conservative whites to internally migrate to other locales. If Lutherton happened to be closer to a city that received a larger flow of Black migrants during the first and second Great Migration, this may have served as a source of intense racial threat that could have increased Republican voting among its white voters. Or perhaps Lutherton absorbed more conservative white migrants fleeing diversifying cities during the 1950s and 60s than Motorville, such that its aggregate political milieu enduringly shifted simply as a result of these compositional shifts.

Finally, I wish that Ternullo had not anonymized the names of the cities she studies. I understand the necessity to protect the privacy of the individuals that she interviewed, but this choice drastically limits the ability of her readers to think critically about her theory. While it is impossible to replicate ethnographic research, more transparency could at least allow other scholars to stress test the central theoretical claims of the book, to better understand the scope conditions of the theory, and to understand how portable the theory is to other similar contexts.

In the end, these questions do little to negate this impressive book’s contribution to the literature. Instead, I hope How the Heartland Went Red inspires other scholars of American political behavior to build on Ternullo’s theory and to test it with different empirical approaches. Students of American politics won’t be able to ignore the important role that local-level institutions play in moderating national political trends after reading this book. And our understanding of American politics will be stronger for it.