Abstract
Polarization may be the most consistent effect of populism, as it is integral to the logic of constructing populist subjects. This article distinguishes between constitutive, spatial and institutional dimensions of polarization, adopting a cross-regional comparative perspective on different subtypes of populism in Europe, Latin America and the US. It explains why populism typically arises in contexts of low political polarization (the US being a major, if partial, outlier), but has the effect of sharply increasing polarization by constructing an anti-establishment political frontier, politicizing new policy or issue dimensions, and contesting democracy's institutional and procedural norms. Populism places new issues on the political agenda and realigns partisan and electoral competition along new programmatic divides or political cleavages. Its polarizing effects, however, raise the stakes of political competition and intensify conflict over the control of key institutional sites.