Do parties change their platform in anticipation of electoral losses? Or do parties respond to experienced losses at the previous election? These questions relate to two mechanisms to align public opinion with party platforms: (1) rational anticipation, and (2) electoral performance. While extant work empirically tested, and found support for, the latter mechanism, the effect of rational anticipation has not been put to an empirical test yet. We contribute to the literature on party platform change by theorizing and assessing how party performance motivates parties to change their platform in-between elections. We built a new and unique dataset of >20,000 press releases issued by 15 Dutch national political parties that were in parliament between 1997 and 2014. Utilizing automated text analysis (topic modeling) to measure parties' platform change, we show that electoral defeat motivates party platform change in-between elections. In line with existing findings, we demonstrate that parties are backwardlooking.