Much work on party strategy assumes that voters will reward particular issue stances with their ballot. Vice versa, much work on voting behavior assumes that parties’ issue stances are designed with vote maximization in mind. We integrate these assumptions into one dynamic model: Parties first strive to emphasize certain policy issues according to their potential to attract new voters while defending existing support—the strategic sweet spot described by “Issue Yield” theory. Among voters, sensitive to such issue priming, these issues acquire higher salience as criteria orienting the voting decision. As a result, the electoral return on effective Issue Yield strategy will manifest itself in a competitive tilt toward the winning party. Overall, we expect vote switching to occur when there is a disparity in the degree to which parties pursue their Yield. We test these hypotheses using data from the Issue Competition Comparative Project, which combines seven pre/post-election voter surveys from Europe and the US with systematic codings of parties’ Twitter campaigns.