Presidential campaigns involve nothing more than “mobilizing the base.” The Republican and Democratic parties toss red (blue?) meat to their respective faithfuls, and then these voters, enthused about their candidate and enraged by the opponent, march to the polls on Election Day. No matter who wins, the electorate appears polarized—two opposing armies staring at each other from their own trenches.
They highlight a very different campaign dynamic: how candidates use “wedge issues” to lure voters from the other party. In the book’s opening example, Ronald Reagan Jr. addresses the 2004 Democratic convention about the benefits of stem cell research—a message targeted at the many Republicans who support such research.
Hillygus and Shields resurrect the venerable notion of “cross-pressures” and reconceive it not as the conflict between partisan and social identities (e.g., black Republicans) but as the conflict between partisan identities and positions on key issues (e.g., pro-choice Republicans). Given current levels of political polarization, such conflicts appear unlikely, but Hillygus and Shields show that nearly all Democrats and Republicans disagree with their parties on at least one issue. Moreover, the extent of cross-pressures has remained constant over time, despite any “ideological realignment” of liberals and conservatives to their natural partisan homes. Because the parties contain multitudes, citizens are not polarized into competing armies. Hillygus and Shields rightly emphasize purple rather than red or blue.
Hillygus and Shields then show that in 2000 and 2004 cross-pressured voters were more likely to be initially undecided, to change their mind during the campaign, to delay their vote decision, and ultimately to defect to the other party. Defections were more prevalent after conventions and debates and in battleground states—suggesting that the campaign encouraged these defections. Hillygus and Shields also delve deeply into a particular instance of wedge politics: Richard Nixon’s “Southern Strategy.” When Nixon scaled back his early support for civil rights and instead expressed opposition to school busing and other similar stances, cross-pressures on racial issues more strongly predicted the defection of white Democrats. As the Republican Party shifted its focus from racial issues to abortion, gay rights, and the like, Hillygus and Shields demonstrate that cross-pressures on moral issues more powerfully predicted Democratic defection.
Hillygus and Shields suggest that wedge politics should become even more prevalent. Because the parties have built databases of voter behavior that include vote history, magazine subscriptions, credit card purchases, and so on, they are now better equipped to target subsets of voters with messages tailored to their interests. Hillygus and Shields show that wedge issues are almost entirely absent from “macro-targeted” media but are more prominent in “micro-targeted” media such as direct mail. Furthermore, those most likely to defect, independents and weak partisans, are most likely to receive mail highlighting wedge issues, suggesting that the parties are using these issues to encourage defections.
In the concluding chapter, Hillygus and Shields discuss both salutary and troubling implications. On the one hand, the electorate is not comprised merely of hardened partisans but of many persuadable voters, and these voters are not simple-minded or capricious but focused on important policy questions. Moreover, candidates are not just making vague promises but also taking potentially divisive positions on real issues. On the other hand, micro-targeted campaigns may stratify the electorate even further into “relevant” voters, who live in important states or belong to important sub-groups, and irrelevant voters—thereby exacerbating existing information asymmetries. Micro-targeting also complicates electoral mandates: if different voters are basing their decisions on very different issues, how can elected leaders draw lessons for governance?
Much of this analysis is persuasive, although three questions linger in my mind. The first is whether partisan defection derives from incongruent issue positions as opposed to, say, evaluations of the incumbent’s performance or of the candidates’ traits. These alternative explanations are not evaluated explicitly and may deserve further attention.
Second is the question of whether wedge issues affect election outcomes, above and beyond their effects on individual voters. Hillygus and Shields have some back-of-the-envelope math calculating the predicted number of partisan defectors in battleground states in 2004, which in turn dwarfs Bush’s victory margin in these states. But they do not disaggregate defectors into Republican and Democratic “disloyalists,” and so it is difficult to tell whether there was a net advantage to either candidate. A similar point can be made about the Southern Strategy. Were Nixon’s victories contingent on wedge politics? It is hard to know.
Finally, while wedge politics may be alive and well, recent elections have been more notable for partisan loyalty than partisan defections. In fact, even as cross-pressures have remained largely constant over time, partisan loyalty has increased. Advances in micro-targeting do not appear to have facilitated effective wedge politics. In 2004, for example, 89% of Democrats supported Kerry and 93% of Republicans supported Bush, according to the national exit poll. By my calculations, partisan loyalty was equally prevalent in battleground states and other states, so campaign activity did not appear to increase aggregate levels of defection. To be sure, Hillygus and Shields explicitly acknowledge that campaigns are about much more than wedge issues, and that candidates also try to reinforce partisan loyalties. But it would be interesting to evaluate which dynamic—defection vs. reinforcement—is more prominent. After all, campaigns can just as easily use micro-targeting to shore up support among their friends as to seduce their enemies.
These questions aside, The Persuadable Voter should prove a cornerstone of contemporary scholarship about campaigns. The theory of wedge politics is compelling, no matter how difficult it may be to encourage partisans to defect in today’s polarized politics. Hillygus and Shields have established cross-pressures as a crucial factor that moderates the effects of campaigns, and their empirical findings constitute striking evidence of such effects. Finally, the book itself is a model for how to present statistical analysis clearly, to mingle social science with lively anecdotes, and to challenge lazy conventional wisdom in provocative ways. It deserves to be read by academics and political practitioners alike.
[Forthcoming in Public Opinion Quarterly]