This paper proposes a model to investigate latent polarization on voters’ support for redistributive policies. It uses a semi-parametric Bayesian approach to demonstrate how latent heterogeneity in the effect of observed covariates leads to different latent structures of polarization in different countries. Previous studies on issue polarization only investigated polarization among observed socioeconomic groups (rich versus poor, white versus non-white), overlooking within-group latent polarizations and cross-group latent coalition in policy preferences. Using ISSP data since 1985, the paper shows that when latent heterogeneity in the effect of observed covariates is taken into account, some OECD countries display tendencies of cross-class pro-redistributive coalitions and within-class polarization in support for welfare policies.