Compulsory voting, electorate expansion and support for an anti-elite candidate

Chile’s return to compulsory voting (CV) expanded the electorate, raising questions about how voters are represented. We examine this issue through Franco Parisi, an anti-elite candidate, in the 2025 election. Using a survey of 6047 respondents and municipal data covering his three campaigns, we find greater relative support for Parisi among respondents without left–right placement. Municipally, his 2025 vote share was positively associated with growth in votes cast and poverty, with poverty more strongly related to support in the Metropolitan Region. Municipalities where Parisi performed better in the first round also recorded higher invalid voting in the runoff. The longitudinal analysis shows that the 2025 association between electorate growth and Parisi’s vote was not statistically different from 2021, although participation expanded far more sharply under CV. These findings suggest that CV may reshape representation through the scale of electorate expansion without creating new electoral relationships.