Dynamics in Partisanship during American Presidential Campaigns

Despite their potential importance, little is known about the nature and prevalence of party identification dynamics within American presidential campaigns. this study reviews existing research to propose three basic contrasting models. it then introduces multivariate state space methods that account for sampling error and survey design effects to evaluate each model’s relative support within daily national survey data of the 1984, 2000, 2004, and 2008 presidential campaigns. the results indicate that the balance of party identifiers had near-certain changes during three of the four campaigns, with campaign events often being associated with these changes. these findings suggest that polls and analyses that fail to allow for sudden shifts in party identifications will mask changes in public opinion. more generally, the findings demonstrate that campaigns shape party coalitions on Election Day, and possibly thereafter. A common way to cast doubts on a survey result is to claim the survey is biased from a skewed sample of party identifiers. this was often the case during the 2004 presidential campaign, when interest groups, pollsters, political scientists, and the news media engaged in prominent debates over whether polls should treat party identification as a relatively stable factor and, thus, use weights or not (macFarquhar 2004; memmott 2004; Abramowitz 2006; newport 2006). Similar debates surfaced in 2012, to the point where conservatives sought out websites like unskewedpolls.com, which adjusted published poll results to account for a believed systematic undersample of republicans. Corwin D. Smidt is an assistant professor of political science at michigan State University, East Lansing, mi, USA. the author thanks Paul Abramson, Brandon Bartels, and Jan Box-Steffensmeier for their help and comments, and especially thanks Herb weisberg for providing the 1984 polling data. Data used in this study were collected by the Annenberg Public Policy Center of the University of Pennsylvania and Decision making information, incorporated. Additional codes needed for replication purposes are available from the author upon request. *Address correspondence to Corwin D. Smidt, Department of Political Science, michigan State University, South Kedzie Hall, 368 Farm Lane, S303, East Lansing, mi 48824, USA; e-mail: smidtc@msu.edu. Public Opinion Quarterly, Vol. 78, Special issue, 2014, pp. 303–329 doi:10.1093/poq/nfu014 at Jrdan U niersity of Sence nd T ecology on July 6, 2016 http://poqrdjournals.org/ D ow nladed from Skeptical partisans typically initiate these debates over survey methodology, but their concerns remain in many ways valid and appropriate. nonetheless, despite partisanship’s considerable influence on voting behavior, scholars know little about the stability of party coalitions over the course of the campaign and whether weighting is viable. Knowing if and how party identifications change during campaigns has direct implications for survey methodology, but it also informs our understanding of campaigns more broadly. Candidates often attempt to attract voters by modifying the image and identity of their party. By examining whether these actions contribute to changes in party identification, we can clarify what role candidates and campaign events play in forming party coalitions. moreover, researchers studying campaign effects often control for partisanship within their analysis of campaign effects but fail to consider the implications of doing so. if the campaign’s influence on voters is directed partly through changes in partisanship, then studies that include partisanship as a controlling factor mask the total effect campaigns have on public opinion. Accordingly, this study explores the prevalence and nature of campaign dynamics in aggregate party identification. i review extant studies of party identification to generate three competing models of party coalition dynamics: a stability model, an enhanced trend model, and a campaign events model. Using Bayesian state space models that test for dynamics while accounting for missing data, sampling error, and survey design effects, i compare the relative performance of these models within national daily survey data from the 1984, 2000, 2004, and 2008 campaigns. model estimates are near certain that the balance of party identifiers changed during three of the four campaigns. moreover, the 2000 and 2008 estimates suggest that party coalitions changed in response to campaign events and in a manner beyond the reflection of retrospective forces. these findings demonstrate that the balance of party identifiers often fluctuates during the campaign and that this movement is at times conditional on campaign events. Consequently, the use of party identification as a weighting or controlling variable will bias estimates of public opinion if partisanship’s dynamics are not accurately identified. more generally, it indicates that campaigns can foster changes in party identification, but the nature of partisanship’s responsiveness varies by election. Presidential campaigns and Party identifications Candidates are focused primarily on winning over voters during presidential campaigns, but they commonly attempt to do so by modifying the public’s perception of their party. By emphasizing issue positions (Petrocik 1996) or attending to ethnic or other social groups (Philpot 2004), parties attempt to strengthen or counter partisan stereotypes (rahn 1993) and broaden the Smidt 304 at Jrdan U niersity of Sence nd T ecology on July 6, 2016 http://poqrdjournals.org/ D ow nladed from appeal of the party label. Campaigns consequently increase citizen knowledge of party symbols and issue positions, especially among the young (Sears and Valentino 1997). Along these lines, the effects of the campaign can go beyond election-specific attitudes and last beyond the campaign. if a campaign effectively modifies the party’s brand, then the distribution of party identifications among Americans is also likely to change. Surprisingly, little is known about whether campaigns have effects on party identification. Studies of dynamics in partisanship over multiple years are extensive and prominent (e.g., Clarke and Stewart 1998; Erikson, macKuen, and Stimson 2002; Green, Palmquist, and Schickler 2002). these studies tend to agree that party identifications change, but they disagree on the meaning and durability of these perturbations. Campbell et al. (1960) originally proposed that party identifications were psychological attachments that were highly durable compared to other attitudes. Party identifications may change in response to external forces, but often revert to their original state after such aberrations, a claim most recently emphasized by social-identity perspectives (Green, Palmquist, and Schickler 2002; weisberg and Greene 2003). the contention of revisionists is that changes in partisanship reflect more than temporary disturbances. Changes represent a meaningful accumulation of retrospective evaluations or prospective gains that have lasting consequences for future political behavior (Fiorina 1981; Achen 1992). revisionist arguments are supported by examinations of aggregate dynamics by Erikson, macKuen, and Stimson (2002), who find that trends in economic evaluations and presidential evaluations have permanent repercussions for future partisanship. However, both theoretical camps are relatively agnostic about the reaction of party identifications to presidential campaigns. Social-identity perspectives recognize that changes in partisanship are possible during campaigns but claim they are unlikely to last (Green and Yoon 2002). For instance, Converse (1976, 124) characterizes noticeable movements in partisanship preceding the elections of 1956, 1968, and 1972 as “wobbles. ” revisionists also allow for changes, but their estimates suggest that presidential approval or economic evaluations produce relatively small immediate effects that take time to accumulate. Erikson, macKuen, and Stimson (2002) estimate that a one-percentage-point change in presidential approval results in only a . 13-percentage-point permanent change in macropartisanship one quarter later. Consequently, they describe most of the change in macropartisanship during the 1984 campaign as a large temporary deviation from equilibrium expectations. moreover, we currently have scattered perspectives and evidence about partisanship’s interaction with campaigns. Evidence of sharp movements that occur right before an election is either from the American national Election Studies (AnES) data (Converse 1976), which have relatively large rates of sampling error, or an aggregation of many Gallup polls each quarter (Erikson, macKuen, and Stimson 2002), where Gallup’s measure enhances partisanship’s responsiveness to current conditions (Abramson and ostrom 1994). Campaign Dynamics in Partisanship 305 at Jrdan U niersity of Sence nd T ecology on July 6, 2016 http://poqrdjournals.org/ D ow nladed from Likewise, some studies find that campaigns recruit independents such that their numbers decline from the prior year (Clarke and Stewart 1998), but such gains in partisanship may be specific to the Gallup question wording (Green, Palmquist, and Schickler 2002). there are only a few studies of the dynamic behavior of party identification within campaigns. Allsop and weisberg (1988) provide the first investigation of daily survey data from the 1984 campaign, finding that partisanship showed clear trends. these results are limited, however, by their inability to determine whether sampling error produced these dynamics. Examining the AnES’s four-wave 1980 major panel study, Brody and rothenberg (1988) claim that much of the observed change in partisanship was systematic. However, Green and Yoon (2002) use the same 1980 AnES data and additional panel data from the 1976 campaign and find that individual-level changes in partisanship rapidly dissipate and