The rightward shift and electoral decline of social democratic parties under increasing inequality

Abstract

Recent electoral results reveal a pronounced decline in the fortunes of Social Democratic parties. Much of the decline debate has revolved around their rightward policy shifts, which have turned Social Democrats away from their founding principle of equality in an age of increasing inequality. Thus, this article examines the interconnections of these major changes in the Western political economy. In doing so, it contributes to the identification of income inequality as a key mechanism moderating Social Democratic policy offerings and their support. It does so through aggregate-level election results and individual-level survey responses on a sample of 22 advanced democracies, over 336 elections, from 1965–2019. Results reveal that rightward economic movements of Social Democrats significantly reduce their vote share under higher levels of income inequality or when they are combined with rightward socio-cultural movements. The findings provide an important explanation for the pronounced electoral decline of Social Democratic parties.