Support bases of left-wing and some liberal (‘progressive’) parties increasingly consist of wealthier voters. This presents a challenge. Though these progressive parties continue to espouse redistributive goals, a decrease in support from low-income voters implies that redistribution will be harder to achieve because parties’ positions on redistribution have been linked to the composition of their support bases. In representative democracies, it is commonly accepted that parties are meant to serve as voters’ representatives in government and that their policies ought to reflect voters’ preferences. This leads to the main question in this study: are progressive parties’ positions on redistribution responsive to the changes in the composition of their support bases? Engaging literature on intra-party politics, representation, political economy, and institutional theories of path-dependence, we use quantitative statistical modeling to examine this question in 27 EEA countries over time (1980-2020). In doing so, we are taking the first step in a larger scholarly agenda aimed at exploring how voter preferences, external institutions, and parties’ appeals to social groups determine parties' positions on redistributive policies and their electoral consequences. Challenging the argument that rational-choice calculations of utility maximization determine parties' behavior, the study introduces other internal and external influences, enhancing our understanding of important democratic practices and the party-voter linkage.