Being heard above the noise: the role of incumbent issue diversity in election campaigns

Historical policy reputations influence voters’ perceptions of parties’ electoral campaigns. In the face of their recent experiences in office, government parties’ thoughtfully crafted electoral messages likely compete for voters’ attention with a wealth of broader information about the government’s policy activities and priorities. For their message to be heard, incumbent parties must offer a focused policy message that draws voters’ attention to the issues they most prioritize. Considering the issue scope of parties’ electoral messages, I hypothesize that incumbency status determines the effect issue appeals have on the votes parties receive. Opposition parties may profit from including more issues, but incumbent parties’ policy reputations limit the potential benefits from diverse appeals. Using evidence from 25 OECD countries over a 60 year period, I find that parties’ incumbent status conditions the effect of issue diversity on parties’ aggregate electoral success. Voters reward incumbents for focusing their platforms, but reward opposition parties for diverse appeals. The results for incumbent parties are robust to extensive sensitivity analyses. The theory and evidence broadly suggest that incumbent parties with more focused policy messages can, at least partially, overcome the weight of their past policy reputations.