Although public opinion research has made tremendous progress in identifying the conditions under which citizens adopt coherent political beliefs, comparatively little attention has been paid to the role of national political context in shaping mass belief system coherence. Using dedicated statistical network models built from representative surveys conducted across 38 European countries between 2002 and 2020, this article demonstrates that national-level attitude systems vary substantially and systematically in overall constraint. Drawing on both a novel, network-derived measure of belief system coherence and node-level centrality metrics, this paper further shows that political systems characterized by programmatic linkages between citizens and political parties sustain far more coherent mass beliefs than those in which party-citizen interactions typically involve personal favors. Furthermore, just under one third of the belief-structuring effect of party-citizen relations is mediated by the relative centrality of citizens’ symbolic ideological attachments within national-level belief systems. Abstract ideological summary positions are not central to all belief systems, but where they are, mass beliefs tend to be more coherent overall.
