Why do voters accede to or abandon social democratic parties in the most recent decades? This chapter analyzes the reasons that motivate voters go choose among parties. Are spatial considerations coming into play, that is, do voters move to parties that are more consistent with their preferences than those they abandon? This chapter tests this argument with European Election Study data from 1999 to 2019 focusing on those respondents who report a different party preference at the time of a survey compared to their past vote recall (“vote switchers”). The data reveal a robust relationship between switching direction and voter preferences, bearing out rational spatial theories of voting. For Social Democrats’ strategy considerations, however, this brings to light an inconvenient fact: Voters abandon their parties for very different reasons heading to a plurality of alternatives. Consequently, no unified party strategy can stop the vote hemorrhage on all fronts of competition.

To what extent does moderation in ideological positioning by social democratic parties affect their short- and long-term electoral fortunes? Do existing social democratic electorates respond differently to moderation from the major parties of the Moderate Left on the economic as opposed to the cultural dimension? Previous research suggests that social democratic parties received an influx of centrist voters post-moderation but that these new centrist voters were less attached to the party and left in later elections, as did left-leaning social democrats frustrated by moderation strategies. This chapter further probes whether there is a link between moderation and individual voters’ shifts from social democratic parties at a later point, by considering a larger number of cases and by differentiating between the economic and cultural dimensions. We examine individual-level data on voting behavior combined with information on mainstream left parties’ ideological shifts in up to fifty elections in sixteen countries over recent decades. The findings show that (a) moderation can have detrimental consequences in the longer term; (b) the consequences of moderation differ across the left-right and cultural dimensions of electoral competition; and (c) the combination of individual-level analysis, with broader contextual and systemic considerations, is essential to fully engage with these questions.

Two widespread narratives attempt to account for the decline of social democratic parties over the past decades. The economic narrative points to these parties’ centrist positioning as the key cause and the Radical Left and Right as the key beneficiaries. By contrast, the cultural narrative focuses on the liberal positions of social democratic parties on new issues relating to cultural issues such as immigration, gender equality, and European integration and points to the Radical Right as key beneficiaries. What links these two narratives is the idea that Social Democrats have alienated the working class. In this chapter, we use individual-level survey data from eight countries to show that although social democratic parties have seen losses among all electoral groups, the voters who left social democratic parties were disproportionately centrist and educated. Second, we find that only a small share of former social democratic voters defected directly to parties of the Radical Right. Instead, social democratic parties lost most voters to moderate right, green, and left-libertarian parties. We additionally show that cultural attitudes play only a small role for choosing between moderate right and social democratic parties. By contrast, they are strongly linked to choices between social democratic and green/left-libertarian parties. These findings cast doubt on both predominant narratives of social democratic decline.