By allowing state officials to respond to the disparate preferences of their constituents in a large and diverse republic, the American federal system opens the door for policy experimentation and significant spatial and temporal variation. However, polarization and the nationalization of state-level partisan politics superficially appear to have bifurcated most of the country into two monolithic blocs—one red, one blue—with policy nuance and democratic responsiveness the likely collateral damage. In such an environment, can state policy making still reflect the will of the people? Thirty years ago, empirical research showed evidence of robust responsiveness. More recent critiques paint a decidedly darker picture of state governments, warning of a democratic deficit, highly unequal responsiveness, and democratic backsliding that rivals or even exceeds concerns at the national level.

Dynamic Democracy boldly pushes back against such claims. Even in an era of nationalized parties and intense polarization, Devin Caughey and Christopher Warshaw find compelling evidence of strong, if imperfect, policy responsiveness at the state level. To be sure, when controversial issues emerge onto the public agenda, considerable disconnects between policy and preferences are common. However, over time, policy makers routinely bend to the popular will.

The book’s core innovation is the coupling of a herculean original data-collection effort with sophisticated methods, which permits causal estimates of the effects of changes in mass preferences on changes in public policy outcomes. Data limitations greatly complicate efforts to measure public preferences across issues over time. Most issues emerge and then drop off the policy (and therefore polling) agenda, and the resulting time series are limited and fragmentary at best when measuring public policy preferences at the national, let alone the state, level. Accordingly, many analyses rely primarily on cross-sectional data. However, this approach inevitably fails to capture the dynamic element of democratic responsiveness and greatly complicates efforts to make causal estimates.

To overcome these limits, Caughey and Warshaw marshal an impressive original dataset by combining data from standard benchmark surveys, such as the ANES, GSS, and CES, with policy-relevant questions from hundreds of public polls housed at the Roper Center for Public Opinion Research. Using sophisticated methods, they carefully construct estimates of mass conservatism and issue-specific policy preferences across states over time. Armed with these measures, Caughey and Warshaw show that changes in mass conservatism do indeed produce more conservative policies, and vice versa, and although the immediate effects of even large shifts in preferences are modest, over time they can be transformative as the effects cumulate. Perhaps more surprisingly, they offer evidence that state governments, particularly on economic policy, are even more responsive in recent decades than in previous eras.

To be sure, this responsiveness is far from perfect. In their analysis of 72 issue areas, state-level policy aligns with majority opinion roughly 60% of the time—better than a coin flip but still far below normative ideals. Southern exceptionalism persists as southern states continue to embrace economic policies that are more conservative than their publics. Historically, both Jim Crow laws and legislative malapportionment undermined democratic responsiveness in the region. And although the gap in responsiveness between white and Black voters closed in the South from the 1960s through 2000, there is at least suggestive evidence that it may have begun to widen again. Similarly, partisan gerrymandering has also had modest but meaningful adverse effects on policy representation in the states. Yet, Caughey and Warshaw’s holistic assessment of democratic representation in the states is decidedly rosier than most recent accounts.

The puzzle, then, is why and how states remain relatively responsive to mass preferences, despite broader political trends that would seem to suggest the presence of important barriers to responsiveness. The first half of the book offers two main explanations. First, polarization itself may have strengthened policy responsiveness in important ways. The ideological gaps between Democrats and Republicans at the state level have grown dramatically over the last 40 years, while intra-partisan differences across states have shrunk. This mass-level polarization, in turn, has resolved the long-puzzling weak relationship between mass conservatism and state partisanship. In recent years, mass ideology and state partisanship have become highly correlated, and partisan control of state institutions has significant effects on policy outcomes. Indeed the effect of partisan control on economic policy conservatism since 1993 is double that observed in earlier eras. Similarly, Republican control now produces increases in cultural policy conservatism, whereas it had no effect in earlier eras. Critically, Caughey and Warshaw interpret this trend as consistent with responsiveness: “By making primary electorates and activist networks more extreme, partisan divergence in the mass public has in turn reinforced and probably exacerbated partisan divergence among political elites” (75).

Second, Caughey and Warshaw find evidence that voters continue to exercise a moderating influence on policy, despite bottom-up–fueled polarization. Even with the growing importance of national tides in shaping state elections, state-specific factors continue to have considerable influence on electoral outcomes; normatively, this influence is incredibly important because it suggests elections still afford an important accountability mechanism through which voters reward or punish incumbents for state-level outcomes. Even in our intensely polarized contemporary era, voters incentivize moderation among their political representatives. Across a range of measures, the data show evidence of a modest but meaningful electoral penalty for ideological extremism. Regression discontinuity analyses also yield important evidence for what Caughey and Warshaw call electoral balancing. Namely, narrowly winning a toss-up gubernatorial race or control of a state house costs the party at the polls in the next election. Collectively, these electoral forces incentivize officeholders to moderate and be responsive to citizen preferences.

Perhaps the book’s greatest limitation is that the individual-level processes that underlie some of the most important aggregate-level dynamics uncovered in the book remain unclear. For example, electoral balancing is a key mechanism incentivizing political responsiveness. The balancing logic suggests that the electoral penalty incurred by winning a governorship or state house control should be greater if a party uses that power to pursue more extreme policies. However, the size of this electoral penalty does not vary with the magnitude of policy changes pursued while in office. Caughey and Warshaw argue that state-level polarization is, at least in part, driven from the bottom up, with polarized primary voters and activists exacerbating elite-level divides. But what has led voters to polarize, if not in response to elite cues? This remains unclear. Similarly, the aggregate-level analyses presented in chapter 3 suggest that state publics have brought their partisan affiliations in line with their ideological orientations. This accords with impressionistic evidence: for example, most white southerners did not first become Republicans and then more conservative, but rather conservative white southerners gradually became more likely to identify with the Republican Party. However, this and other aggregate-level patterns are sometimes in tension with microlevel studies of individual behavior. Ultimately, this is not so much a weakness per se as it is a clear signpost for the need for more research to better understand these disjunctions.

Dynamic Democracy is one of the most important books written on state politics in years, and it offers a stark challenge to narratives lamenting democratic decline in contemporary American politics. The book’s argument, data, and findings are sure to serve as a catalyst for new research in the field, and it will be of interest to students and scholars from across political science and related disciplines.