Polit Behav (2016) 38:337–354 DOI 10.1007/s11109-015-9315-7 ORIGINAL PAPER Sorting and the Split-Ticket: Evidence from Presidential and Subpresidential Elections 1 2 Nicholas T. Davis • Lilliana Mason Published online: 28 August 2015 Ó Springer Science+Business Media New York 2015 Abstract Although prior research demonstrates that strong partisans are less likely to cast a split-ticket, recent scholarly work hints that partisan-ideological sorting— the matching of an individual’s partisan and ideological identities—may play a comparatively stronger role in shaping this voting behavior. Simply, if a high degree of congruence between identities underscores psychological orientations that pre- vent association with an out-group, then highly-sorted voters should be less likely to cross-party lines within the voting booth. Using the 1972–2012 ANES Time-Series and 2010 CCES surveys, we provide evidence that demonstrates that a high degree of partisan-ideological sorting produces the strongest negative effect on split-ticket voting among a variety of alternative explanations at both the national and subna- tional levels. We then supplement these analyses with 1992–1996 ANES panel data to demonstrate how changes in sorting over time affect this voting behavior. Our results indicate that although an increase in partisan strength alone is insufficient to reduce an individual’s propensity to cast a split-ticket, an increase in identity sorting over time has a strong negative effect on split-ticket voting. We conclude with a brief discussion about the consequences of identity convergence; namely, that sorting fosters a unique form of electoral ‘‘polarization.’’ Keywords Sorting Á Ticket-splitting Á Electoral polarization Electronic supplementary material The online version of this article (doi:10.1007/s11109-015-9315-7) contains supplementary material, which is available to authorized users. & Nicholas T. Davis [email protected] 1 Department of Political Science, Louisiana State University, 240 Stubbs Hall, Baton Rouge, LA 70803-5433, USA 2 Department of Government and Politics, University of Maryland, College Park, 3140 Tydings Hall, College Park, MD 20742, USA 123 338 Polit Behav (2016) 38:337–354 Although the study of split-ticket voting has received generous scholarly attention (Campbell and Miller 1957; Beck et al. 1992; Burden and Kimball, 2004; Davis 2015), relatively little research has considered how the effects of mass sorting have contributed to the prevalence of split-tickets.1 However, recent work on partisan- ideological sorting—the process whereby an individual’s partisan and ideological identities converge—has clear implications for how scholars traditionally consider ‘‘motivated’’ explanations of ticket-splitting behavior. Simply, if a high degree of integration between congruent identities underscores significant psychological orientations that prevent association with an out-group (Roccas and Brewer 2002; Brewer and Pierce 2005), then highly-sorted voters should be less likely to cross party lines within the voting booth. As a result of these increasingly tribal attachments (c.f. Mason, 2015), we argue that split-ticket voting should be extraordinarily rare for individuals with strong, overlapping ideological and partisan identities. Using the 1972–2012 ANES Time-Series and 2010 CCES surveys, we provide firm evidence that partisan-ideological sorting routinely produces the strongest negative effect on split-ticket voting among a battery of alternative explanations at both the national and subnational levels. We then supplement these analyses with 1992–1996 ANES Panel Study data, which cover a period of time in which Americans’ political identities were in considerable flux and partisan-ideological sorting rapidly accelerated (Mason 2015), to demonstrate the causal effects of changes in sorting on vote choice. Interestingly, these results indicate that although an increase in partisan strength alone is insufficient to motivate a reduction in an individual’s propensity to cast a split-ticket, an increase in sorting over time has a strong negative and significant effect on this voting behavior. We conclude with a brief discussion about why previous work that concentrates solely on the strength of partisan attachments undersells the role that multiple, consistent political identities play in creating a unique form of electoral ‘‘polarization.’’ Preferences, Identity, and Split-Ticket Voting Although institutional conditions play a role in structuring the frequency of ticket- splitting (Burden 2002), the earliest scholarly work on split-ticket voting clearly emphasized the primary role that individuals’ partisan preference orientations play in producing straight or split-tickets (Campbell and Miller 1957).2 Indeed, if electoral choice reflects the degree to which preference orientations are integrated 1 Levendusky (2009) includes one analysis of how a form of attitudinal sorting affects split-ticket voting in the narrow window of time from 1992 to 1996, but this form of sorting is appreciably different from our understanding of partisan-ideological sorting, which we expand upon below. 2 Two important institutional conditions are candidate incumbency and availability. First, incumbency increases the likelihood of split-tickets because the name recognition enjoyed by incumbent candidates is often significant enough to attract out-party voters (Beck et al. 1992; Burden 2002). Second, the actual availability of in-party candidates is related to split-ticket voting insofar as candidates running unopposed may attract voters who would not, under other circumstances, cast a vote for that candidate (Burden and Kimball 2004). 123 Polit Behav (2016) 38:337–354 339 into an individual’s partisan consciousness, then clear partisan preferences should result in straight-ticket voting (Lavine et al. 2012). Conversely, for individuals with weakly-rooted or conflicted preference orientations, conflict between these prefer- ences should introduce instability into electoral decision-making (Campbell and Miller 1957),3 while indifference—a complete lack of communicable partisan preferences—should generate the highest likelihood of casting a split-ticket because partisan attachments are only nominally integrated into the indifferent individual’s partisan self-image (Davis 2015). However, while these preference orientations underscore the importance of singular, conflicted, and absent partisan motivations, it is the underlying partisan self-image—or political identity—that fundamentally shapes voting behavior generally (Green et al. 2002; Greene, 2004) and ticket-splitting behavior specifically (Beck et al. 1992). At its core, this is a social identity conceptualization of partisanship that suggests that electoral decision-making should primarily be a function of the strength of the affective connections that an individual shares with a particular party (Campbell et al. 1960; Greene 1999, 2002, 2004; Iyengar et al. 2012; Huddy et al. 2015). Thus, if ‘‘partisanship is the most prominent political identity because parties are the groups that directly compete for power in the political realm, and competition between groups increases the salience of competing group identities’’ (Mason 2015, p. 130), then individuals who strongly identify with a particular party should engage in behaviors that are consistent with or on behalf of those parties (Huddy 2001; Tajfel and Turner 1979). Throughout the literature on split-ticket voting, the connection between the strength of partisan identity and an individual’s propensity to cast a split-ticket is consistently noted in both presidential and subpresidential elections (Campbell and Miller 1957; Beck et al. 1992; Burden and Kimball 2004; Mulligan 2011; Davis 2015). Yet, recent research on partisan sorting—or the convergence of an individual’s partisan and ideological identities—suggests that accounting solely for an individual’s partisan identity may under-estimate the effect that strong and, importantly, consistent political identities have on split-ticket voting. Indeed, we suspect that for these highly-sorted individuals, the likelihood of casting a split- ticket should be particularly low. The Role of Sorting Recent research has shown that partisan-ideological sorting is driving increasing levels of social polarization, which includes partisan prejudice, political activism, and anger (Mason 2015). This is a distinct type of polarization, affecting judgment, action, and emotion, as opposed to the rational assessments of policy outcomes that characterize issue polarization. We believe this distinction is particularly useful because separating social polarization from issue polarization allows scholars to more precisely examine 3 The cross-pressured voter—who is ‘‘attracted to each party by one set of opinions and repelled by another’’ (Berelson et al. 1954, p. 200)—is likely to cast a split-ticket as a function of this ambivalence (Mulligan 2011). 123 340 Polit Behav (2016) 38:337–354 the nature of polarization, generally, and the outcomes of sorting, specifically. In particular, it runs contrary to claims that partisan-ideological sorting and polarization are one and the same (Fiorina et al. 2005, 2008; Fiorina and Levendusky 2006), while also addressing ongoing debates in political science literature over the very nature of polarization itself (e.g. see Abramowitz 2010 versus Fiorina et al. 2005, 2008). We argue here that the social elements of this polarization are capable of motivating voters to purify their