Incumbent vulnerability and entry in gubernatorial elections: The case of former governors

• Former governors enter general elections strategically.
• We find former governors follow the rational actor model of candidate entry.
• Former governors are more likely to enter elections against vulnerable incumbents.
• Former governors are more likely to enter elections when unemployment increases.

The vulnerability hypothesis predicts strategic, quality candidates only challenge weak incumbents. House election studies support this hypothesis. State level analyses produce mixed results. We test whether incumbent vulnerability affects the entry of one kind of strategic actor – former governors. Former governors are an ideal test case. Having already served in the state's highest office, they represent the highest quality and perhaps most strategic candidates who run for state office. Our results show that performance in the previous election, one measure of incumbent vulnerability, does not affect former governor entry. However, incumbent vulnerability measured as recent economic performance and number of other quality candidates appearing in a former governor's party primary does affect entry in general elections.