Identifying extreme European parties’ ideological positioning across countries

Understanding ideological positioning is essential for analyzing party systems and electoral competition in Europe. This paper uses the data from the 2024 wave of the Chapel Hill Expert Survey (CHES 2024) to investigate European political parties with two objectives: (i) identifying ideological extremes and (ii) examining cross-country patterns in party positioning. We employ Archetypoid Analysis (ADA), a novel statistical method that detects representative ideological extremes in multivariate data. Focusing on general left-right, economic, and sociocultural orientations, and specific policy areas such as immigration, redistribution, and climate change, we map the European ideological space and identify parties that occupy its edges. We then analyze how party positions relative to ideological archetypoids relate to stances on key political issues and EU policies, and how these relationships vary across European countries. In detail, we assess the influence of party agreement with political issues and EU policies on their proximity to left, center, or right positions and, using linear mixed-effects models, we also account for cross-country variation. This approach allows us to evaluate whether observed patterns are consistent across national contexts or differ significantly between countries. The findings also carry policy relevance by clarifying which ideological configurations are associated with support for or opposition to key EU policies. The observed cross-country heterogeneity suggests that European-level initiatives may encounter differentiated political constraints, with implications for policy feasibility and coalition dynamics across national contexts.