Abstract: | In every election cycle the fate of some candidates is determined by partisans who defect from their usual voting habits to cast a ballot for the candidate of the opposing party. Defections in congressional elections have been attributed to incumbency, presidential approval, partisan strength, and factors related to individual voters. Our systematic assessment of the impact of issues on voter defections shows that party‐owned issues and performance issues associated favorably with one party affect the likelihood of partisan defections. The results suggest that congressional candidates can use issues to draw supporters away from the opposing party and to keep partisan voters loyal. |