This article sets out to analyze whether political parties adjust their policy positions in response to public opinion polls. While research agrees that political parties respond to preference changes in the electorate, it usually considers past election results as the decisive yardstick by which political parties' strategic calculi are guided. In this regard, previous work has shown that parties react to their electoral performance in previous elections and to vote gains and losses of competing parties. These models thus assume that election results - often more than three years before the election campaign - are decisive in explaining the strategic behavior of political parties.

Surprisingly, we know less about whether political parties respond to short(er)-term trends in public opinion. Being confronted with clear messages concerning voters’ preference structures, as shown by public opinion polls, I argue that political parties should be responsive to public opinion polls to maximize their vote share. Linking monthly data on citizens' vote preferences and data on parties’ policy positions, this article investigates whether and under which circumstances political parties respond to polling results rather than past election results. Covering a large number of European democracies since the 1950s, the resulting findings will have important implications for our understanding of the dynamics of party competition and elite responsiveness.