Do electoral systems and intra-party candidate selection procedures influence the degree to which parties act in unison? Whereas the theoretical literature is quite clear about the hypothetical effect of these institutions, empirical evidence is mixed. In this article, I solve the puzzle and theorize about the interactive effects of elections and selections on parties’ behavior. I argue that the effect of candidate selections depends on the electoral environment within which they operate. Specifically, in an electoral environment that creates incentives for candidate-centeredness, the less restrictive the selection method a party uses, the less unified its record; whereas in an electoral environment that emphasizes party-centeredness, the effect of selections on unity is more muted. Using the electoral reform and divergent selection mechanisms characterizing Israel during the last three decades and utilizing Rice Scores, I provide support for the conditional effect of electoral systems and selection procedures on party behavior.