Ideological polarization in roll call votes in constitutional conventions: The case of Chile in 2021–2.

This article examines the factors influencing ideological polarization in the 155-member Chilean constitutional convention (2021–2022), which uniquely included a majority of independents alongside party-affiliated members. Analyzing 4,669 roll call votes using absolute WNominate scores, the study finds that party members exhibited lower levels of polarization compared to independents, while prior legislative experience had no significant effect. Additional findings indicate that convention members who introduced more constitutional bills and those representing indigenous minorities were more polarized, whereas women and older members tended to be less polarized. The results suggest that in institutionalized party systems allowing independents to compete on equal footing, a higher presence of independents may increase polarization, highlighting the role of political parties in moderating legislative behavior within constitutional conventions.