Following any hard-fought primary battle, a group of voters will be left without their candidate of choice in the general election. How exactly they respond to this situation — whether they support the party’s nominee, defect to the other party’s candidate, or become disillusioned and don’t participate — is of great interest to scholars and election observers. Moreover, there is often talk within political parties that divisive primary battles need to be ended quickly in order to close ranks and consolidate resources.

A 2010 Public Opinion Quarterly study from Harvard University, Duke University, and the Associated Press, “‘Sour Grapes’ or Rational Voting? Voter Decision Making among Thwarted Primary Voters in 2008,” looks at data from the Associated Press-Yahoo News 2008 election panel study, which analyzed a set of 2,500 voters who participated in the long Democratic nominating contest, pitting Barack Obama against Hillary Clinton. The scholars note that “there is a rich political science literature that finds that divisive primaries harm the party nominee because voters supporting losing candidates are less likely to vote and more likely to defect.”

The study’s findings include:

• Overall, 71% of those voters who preferred Clinton voted for Obama in the general election, meaning there was a “nontrivial number” who did not support the Democratic Party nominee.
• Analysis suggests that Clinton supporters voted for Obama in the general election if “they agreed with him on the issues.” In sum, “Clinton voters were not simply bitter women or working-class Whites unwilling to cast a ballot because of ‘sour grapes.’ Rather, our analysis offers the simple conclusion that Clinton voters made up their minds on the basis of fundamental considerations; so, political conservatives and those who supported the War in Iraq were the most likely Clinton voters to defect to McCain.”
• Put another way, the study’s analysis found that “psychological disaffection, or ‘sour grapes,’ accounted for only a very small portion of general election defections. And, despite concerns that working-class Whites would turn to McCain in droves to avoid casting a ballot for a Black candidate, we find that the impact of negative racial attitudes, while certainly significant, was perhaps smaller than expected.”
• Living in a battleground state made Clinton supporters more likely to voter for Obama on Election Day. Relative to those Clinton voters in uncompetitive states, those living in battleground states showed an increase in support overall for Obama by 8.3 percentage points, resulting in a “pro-Obama shift in the total general election outcome of about 1.5 percentage points.”

The authors conclude, “Although our analysis is necessarily limited to the 2008 contest, our findings nevertheless contribute to a broader understanding of the role that primary elections play in shaping general election contests…. Our analysis offers individual-level results that call into question the longstanding assumption that thwarted voters will necessarily stay home or defect to the opposing-party candidate because of hard feelings from a divisive nomination phase.”

Tags: elections, presidential primary, primary battle