The Shift Toward Extremity Among Self-Identified Moderate Partisans

Empirical work shows that partisans are disproportionately attracted to extreme allies on their own political side compared to moderates, a phenomenon called political acrophily. We argue that this preference for extremes also shapes the beliefs they adopt: many citizens who describe themselves as moderate partisans increasingly endorse the most extreme positions on core policy issues. We call this pattern belief acrophily: the tendency to hold predominantly extreme positions on political issues in relation to one’s own political identity. Using American National Election Studies data from 1972–2024, we show that belief acrophily has risen sharply over time: by 2020 and 2024, moderate Democrats and Republicans were more likely to place themselves at the extreme ends of issue scales on social benefits, health care, and race than at the midpoint. Panel data reveal that moderate partisans with extreme views are substantially more likely to adopt stronger partisan identities in the future. This analysis suggests that polarization is deepening not only through increased issue position sorting according to party membership, but also through intensifying extremity of moderates’ positions on concrete issues.