To what extent do vice presidential picks influence voting behavior in presidential elections? Does the VP choice really matter? This perennial topic has generated much debate over the years.
Generally, it is accepted that vice presidential candidates are of minor importance to the outcome of the election. However the recent attention given to candidates such as Gov. Sarah Palin has reinvigorated the discussion about the potential impact that vice presidential candidates have on voter choice.
Traditionally, vice presidential candidates draw considerable media attention and interest over the span of the election cycle, especially around convention time (when voters speculate the presidential candidate’s choice of running mate) and during the nationally televised vice presidential debates.
Positive coverage from such events usually fuels a bounce in the polls, however the impact of such “buzz” seems to be short-lived. According to Romero, a debate’s half-life appears to be fairly short. Aggregated data showed that the partisan advantage gained post-debate returned to pre-debate levels after a mere seven days.
While it seems that positive media coverage barely influences the polls, one must wonder whether overall feelings of the candidate affect voter choice.
In 1995, Wattenberg investigated the extent that favoring the other party’s vice presidential candidate made a voter defect from his or her presidential choice. Data from 1968 to 1992 showed that about 11% of major-party voters had split preferences for presidential and vice presidential candidates. Surprisingly, an examination of split preference voters revealed that they are marginally more educated than voters with consistent preferences. Using a multivariate analysis, Wattenberg determined that even after controlling for party, ideology and likes and dislikes of presidential candidates, vice presidential candidates remained a significant factor in voting behavior.
Nonetheless in 2001, Romero presented conflicting findings between aggregate-level and individual-level analyses. He believed that individual-level results created exaggerated estimates of the influence that vice presidential candidates had on the presidential vote. After controlling for rationalization effects, he found that while presidential candidate evaluations retained a statistically meaningful influence on the election results, vice presidential candidate evaluations did not. Romero concluded that vice presidential evaluations are insignificant after voters’ predispositions are controlled, but that they may indirectly influence the vote.
In 2010, Grofman extended Wattenberg’s attempt by analyzing the data of four additional elections. He used a weighted average approach and found that the net impact of a vice presidential candidate is generally less than 0.6% in terms of getting voters to cross party lines. In addition, he discovered that conflicted vice presidential preference usually favors Democrats.
Overall, these studies suggest that it is increasingly difficult to separate out the effects of a certain vice presidential candidate from the party with which he or she is running. Scholars warn that the data reported may “understate the impact of vice presidential selection on choice because voters modify their views of the president based on vice presidential selection.” Therefore the results may be “contaminated” by unmeasured variables such as campaign contributions or campaign activism.
Grofman, B. and Kline, R. (2010), Evaluating the Impact of Vice Presidential Selection on Voter Choice. Presidential Studies Quarterly, 40: 303–309
Romero, D. W. (2001), Requiem for a Lightweight: Vice Presidential Candidate Evaluations and the Presidential Vote. Presidential Studies Quarterly, 31: 454–463
Wattenberg, M. P. (1995), The Role of Vice Presidential Candidate Ratings on Presidential Voting Behavior. American Politics Research, 23: 504-514