Political cleavages are not born overnight. They emerge gradually as structural divisions translate into collective identities and find organizational expression in party competition. The expansion of higher education across Europe has produced one of the most consequential transformations of social structure in recent decades, generating systematic differences in values, attitudes, and political behavior between educational groups. Yet whether these differences amount to a political cleavage remains an open question.

This paper asks two related questions: when did educational divisions begin to structure electoral competition, and where has this process advanced sufficiently to constitute a cleavage? To address the first, we track how strongly educational divisions have structured vote choice across a diverse set of European countries over several decades, examining whether observed trends reflect shifts in how educational groups vote or simply changes in their relative size. To address the second, we evaluate where educational divisions simultaneously meet the full conditions of cleavage formation. Drawing on social identity theory we ask whether educational attainment gives rise to intergroup conflict grounded in an education-based identity, and whether such conflict is translated into party competition.

Results reveal a heterogeneous and uneven process. While educational differences in voting behavior are widespread, the strength of the educational cleavage varies across countries. This variation reflects substantial cross-national differences in group identification and intergroup conflict, and only in a limited number of countries do structural differences, identity formation, and party-based mobilization align. Broadly, these findings stress the need to assess the identity dimension when evaluating claims about new political divides, as it represents the required element for stability over time.