Catchall or Catch and Release? The Electoral Consequences of Social Democratic Parties’ March to the Middle in Western Europe

Abstract
Although the move to the center of many European Social Democratic parties in the 1990s was first rewarded with victories, these parties have since faced a remarkable electoral drought. What explains the seeming inability of these catchall parties to cast a wider but sustainable net for voters? Incorporating a temporal dimension helps explain when and why the broadening of party platforms fails and produces counterintuitive electoral outcomes. Our empirical study analyzes the votes of individuals in three European countries in the past three decades. The individual level allows us to track changes in parties’ voter structures, which are necessarily omitted from studies using aggregate vote shares. Our findings indicate that current analyses of the electoral effects of strategy shifts are misleading inasmuch as they fail to account for individual-level motivations for vote switching.