Mapping EU Solidarity with Large Language Models (LLM): Evidence from European Electoral Manifestos (2009–2024)

Faced with a prolonged ‘polycrisis’, the European Union has demonstrated remarkable resilience over the past 15 years, not least through a renewed emphasis on collective support and cross-national solidarity. Recent scholarship has identified this as part of a broader 'bonding' strategy of polity maintenance: an attempt by European elites to reinforce citizens’ sense of common belonging. Yet the extent to which this ‘social turn’ was accompanied by a recalibration of the ideological landscape of party politics at the national level within EU member states remains underexplored from a comparative perspective. This article examines how political parties have articulated the bonding dimension of European integration across four European elections (2009, 2014, 2019, and 2024). It analyses whether parties have increasingly framed the EU as a community of solidarity and social protection, and how these orientations vary by ideology, region, and time. Methodologically, the paper employs large language model (LLM)-based text analysis of the Euromanifestos corpus across all EU Member States, allowing a systematic mapping of how EU solidarity-related concepts – such as redistribution, employment protection, or poverty mitigation - have evolved in party discourse. Corroborating recent work on elite strategies to sustain integration and citizen support, this study shows how the bonding dimension of the EU polity gained prominence amid economic, social, and geopolitical crises, and how it interacted with questions of authority (binding) and boundaries (bounding). By shedding new light on the partisan construction of EU solidarity as a political resource, the findings contribute to debates on Social Europe, party perceptions of economic and social integration, and the scope for new forms of EU action in the social and employment policy domains.