This paper studies the relationship between incumbents’ performance and political extremism, both with theory and data. The theory is based on a spatial model of political competition in which voters use the incumbent’s performance in office to update their beliefs about his competence. A better performance leads to the incumbent’s electoral advantage and so allows him to announce a more extreme platform closer to his bliss point. His challenger, in turn, faces electoral disadvantage and so announces a more moderate platform in order to compensate for it. To test these predictions, we use the data on incumbents’ performance in natural disaster relief and ideological positions of the candidates in the U.S. House of Representatives elections for the time period 2000–2012. The empirical evidence shows that a better performance in post-disaster recovery is associated with more extreme ideological positions of the corresponding incumbents and more moderate ideological positions of their challengers. These and other empirical results are in line with the model predictions.

本文从理论和数据两个方面研究了现任者的表现与政治极端主义之间的关系。该理论基于政治竞争的空间模型，在该模型中，选民利用现任者在任期间的表现来更新他们对其能力的看法。更好的表现会带来现任者的选举优势，从而让他能够宣布一个更接近他的幸福点的更极端的平台。反过来，他的挑战者面临选举劣势，因此宣布了一个更温和的平台以弥补这一劣势。为了检验这些预测，我们使用了 2000 年至 2012 年期间在位者在自然灾害救援中的表现和候选人在美国众议院选举中的意识形态立场的数据。经验证据表明，更好的灾后恢复表现与相应在位者更极端的意识形态立场和挑战者更温和的意识形态立场有关。这些和其他实证结果与模型预测一致。