Abstract:
Populist governance is fundamentally at odds with constitutionalism. As a political project, populism rejects constraints on "the will of the people," including those essential to liberal-democratic constitutions. Yet, the extent to which elected populists actually undermine constitutional order remains contested. This article presents the first empirical analysis of whether constitutional compliance declines following the electoral success of populist parties in parliament and government. Using novel indicators of party populism and constitutional compliance, we find that the entry of populists into government leads to an erosion of constitutional norms, while their mere parliamentary presence has no systematic effect. This negative impact is primarily driven by a weakening of political and civil rights. Our results further show that populist parties-as distinct from individual leaders-are the primary drivers of noncompliance, and that the ideological orientation of these parties predicts the extent of their threat to constitutional order.