Chapter 12 Further Reading: Partisanship, Polarization, and Sorting

Ten annotated entries on polarization, sorting, and their consequences for democratic politics.

1. Abramowitz, Alan. The Great Alignment: Race, Party Transformation, and the Rise of Donald Trump. Yale University Press, 2018.

The most comprehensive and accessible account of partisan sorting and its political consequences by one of the field's most productive researchers. Abramowitz traces the transformation of party coalitions from the 1960s through the Trump era, with particular attention to the role of racial attitudes in driving white voters toward Republicans. Data-rich and clearly written for non-specialists. Chapter 3 on ideological sorting and Chapter 5 on affective polarization are especially relevant to this chapter's themes.

2. Iyengar, Shanto, Gaurav Sood, and Sean Westwood. "Affect, Not Ideology: A Social Identity Perspective on Polarization." Public Opinion Quarterly 76, no. 3 (2012): 405–431.

The paper that brought "affective polarization" into mainstream political science discourse. Iyengar and colleagues demonstrate, through a series of ingenious experiments, that partisans are willing to discriminate against out-party members in non-political contexts (scholarship decisions, hiring choices) at rates comparable to racial discrimination in earlier eras. The finding that partisan hostility has become as intense as racial hostility — measured by similar behavioral outcomes — is both striking and sobering.

3. Levendusky, Matthew. The Partisan Sort: How Liberals Became Democrats and Conservatives Became Republicans. University of Chicago Press, 2009.

The definitive political science treatment of partisan sorting at the mass level. Levendusky traces the mechanism by which elite polarization — the dramatic sorting and extremism of elected officials — filters down to mass audiences and induces ordinary voters to align their party identification with their ideological positions. Clear causal argument with solid empirical grounding. The core claim: sorting is largely driven from the top down, not the bottom up.

4. Mason, Lilliana. Uncivil Agreement: How Politics Became Our Identity. University of Chicago Press, 2018.

Accessible and compellingly argued, Mason's book connects partisan sorting to affective polarization through the lens of social identity theory. Her key insight: as social identities "stack" (race, religion, education, and party all aligning together), partisan hostility intensifies even if policy disagreements don't grow. When "Democrat" correlates perfectly with "urban, college-educated, secular, non-white" and "Republican" with "rural, non-college, religious, white," every political disagreement feels like an attack on fundamental identity. Excellent for students interested in the psychological mechanisms of polarization.

5. Abramowitz, Alan, and Steven Webster. "The Rise of Negative Partisanship and the Nationalization of U.S. Elections in the 21st Century." Electoral Studies 41 (2016): 12–22.

The paper that coined "negative partisanship" and rigorously documented the nationalization of elections using presidential-to-congressional correlation data. Abramowitz and Webster show that the primary driver of straight-ticket voting in recent cycles is not enthusiasm for one's own party but hostility to the opposing party. The empirical documentation of nationalization across multiple electoral cycles is particularly useful for analysts.

6. Bishop, Bill. The Big Sort: Why the Clustering of Like-Minded America Is Tearing Us Apart. Houghton Mifflin, 2008.

The popular account of geographic partisan sorting. Bishop's thesis — that Americans are increasingly choosing to live in ideologically homogeneous communities — is argued through a combination of political data and social observation. The book's empirical claims have been refined by subsequent academic research (particularly regarding compositional vs. behavioral sorting), but it remains an important and readable introduction to geographic polarization and its social consequences.

7. Fiorina, Morris P., Samuel J. Abrams, and Jeremy C. Pope. Culture War? The Myth of a Polarized America. 3rd ed. Pearson, 2011.

The counterpoint to the polarization narrative. Fiorina and colleagues argue that ordinary American voters are not as polarized as elite discourse suggests — that most Americans hold moderate, nuanced views and that the apparent polarization in electoral and cultural debates reflects elite polarization rather than mass polarization. Controversial but important reading; the debate between Fiorina's position and Abramowitz's provides an excellent grounding in the empirical and definitional disputes in polarization research.

8. Hopkins, Daniel J. The Increasingly United States: How and Why American Political Behavior Nationalized. University of Chicago Press, 2018.

The most comprehensive empirical treatment of electoral nationalization. Hopkins analyzes decades of presidential, gubernatorial, Senate, and House election data to document the growing correlation between presidential and down-ballot vote shares. The book goes beyond documentation to analyze causal mechanisms — particularly the role of media change and information environments in driving nationalization. Essential reading for analysts working on down-ballot races.

9. Sides, John, Michael Tesler, and Lynn Vavreck. Identity Crisis: The 2016 Presidential Campaign and the Battle for the Meaning of America. Princeton University Press, 2018.

A rigorous and readable account of the 2016 presidential election that situates it in the context of long-run trends in partisan sorting, racial attitude polarization, and the nationalization of identity. Particularly valuable for its treatment of how racial and identity-based attitudes, which had been sorting with party identification over decades, crystallized in the 2016 election in ways that confounded analysts who were using pre-sorting models.

10. Westwood, Sean J., and Erik Peterson. "The Inseparability of Race and Partisanship in the United States." Political Behavior 42 (2020): 1185–1204.

An empirical examination of how racial identity and partisan identity have become deeply intertwined in contemporary American politics — so much so that they are often difficult to disentangle experimentally. The paper has important implications for understanding what affective polarization is measuring and for interpreting any experiment that manipulates party labels without controlling for racial coding. A methodologically sophisticated contribution that raises important questions about the interpretability of affective polarization research.