Is Militant Democracy Effective? Anti‑System Party Bans and Democratic Stability

As democratic regimes face increasing pressures from anti‑system actors, scholars and practitioners debate whether democracies should respond with formally illiberal defenses. “Militant democracy” – the use of coercive, legal, or institutional means to block anti‑democratic actors – often includes banning parties judged to threaten the democratic order. Normative debates about the admissibility of such measures are long standing, but there is remarkably little systematic evidence on whether party bans actually strengthen democracy. This paper presents the first large‑N empirical test of the effects of banning anti‑system parties on democratic stability. We compile a panel of country‑year observations from democracies between 1945 and 2024 using V‑Dem data to identify state actions that remove anti‑system parties from the political arena. We examine three outcome dimensions: (1) public confidence in democratic institutions; (2) democratic backsliding, operationalized as gradual declines in democratic quality; and (3) democratic breakdown, defined as the replacement of a democratic regime by an authoritarian one. We use Bayesian panel models to estimate effects on confidence and backsliding; and survival analysis to assess effects on the timing of regime breakdown. To illustrate causal mechanisms and contextual variation, we complement the quantitative analysis with a paired study of paradigmatic post‑war cases in West Germany and Turkey. While Germany often ranks as the go-to example of successful militant democracy, anti-system party bans in Turkey are said to have contributed to autocratization. These cases show how judicial framing, elite consensus, and the presence of extra‑parliamentary mobilization shaped whether bans stabilized or polarized the polity.