Dimensions of division: structuring ideological polarization during Poland’s democratic backsliding

Research on democratic backsliding increasingly views mass polarization as a mechanism that facilitates democratic erosion. This study examines trajectories of ideological polarization in Poland between 1997 and 2023, a period encompassing democratic backsliding whose onset is typically dated to 2015. Using repeated issue-based questions from the Polish National Election Study (POLNES), we distinguish three aspects of polarization: radicalization of individuals’ positions on single issues, issue alignment (system-level correlation of issue positions across different domains), and issue partisanship (the extent to which issue positions are explained by party preferences). We find no evidence of increased single-issue radicalization over the studied period. By contrast, both issue alignment and issue partisanship increased, particularly on socio-cultural issues, with little change on economic issues. These trends are not linear: they emerge around the 2011 election and persist thereafter. This pattern is consistent with theories that view changes in mass polarization as facilitating conditions for democratic backsliding. Additionally, our findings highlight the heterogeneous nature of polarization and show that focusing on single issues or unidimensional ideological scales can obscure important changes in the structure of mass belief systems.