While previous research on the reciprocal effects of citizens' issue attitudes and their party support emphasize citizens' issue positions, political competition revolves equally around issue salience, i.e., debates over which issue areas political parties should prioritize. Using multi-wave panel data from Germany and Great Britain, we analyze the reciprocal effects of citizens' issue salience and their party support over the period 1984-2009, and we conclude that citizens' issue priorities both influence and are influenced by their party attachments, and, moreover, that these effects are linked to parties' long-term policy emphases as articulated in their election manifestos. This effect is strongest among supporters of a small issue-orientated niche party, the Greens. [ABSTRACT FROM AUTHOR]