How do parties decide when to campaign on valence issues given high degrees of uncertainty? Although past studies have provided evidence of transnational emulation of parties' position-taking strategies, these findings do not directly apply to saliency strategies. Moreover, the exact diffusion mechanism remains largely elusive. Based on the issue saliency literature, this study develops novel theoretical propositions and argues that conscious learning enables parties to infer the relative utility of emphasizing consensual issues during an electoral campaign. The proposed theory gives rise to different expectations at the domestic and transnational levels because of the distinct logic of issue competition. By analyzing environmental issue emphasis in party manifestos, the authors find direct transnational dependencies and indirect spillover effects among the parties' saliency strategies. They identify conscious learning, rather than mere imitation or independent decision making, as the diffusion mechanism at work. Yet, in line with saliency-based theories, electoral competition mutes the diffusion of electoral strategies domestically.