Introduction to the Special Section – ECPR 2021 Joint Sessions ‘Militant Democracy: New Challengers and Challenges’ – metamorphoses of a Cold War concept – new challengers intensify challenges for militant democracy – evaluation of the effects and effectiveness of militant democracy – new conceptual and normative approaches broaden concept of militant democracy – risk of ‘concept stretching’ – minimal common recognisable core

Impact of electoral system design on democratic self-defence – ‘informal’ (content neutral) militant democracy instrument – the minority to majority effect (assigning majoritarian power to political minorities) increases risk of democratic backsliding – minority to majority goes beyond conventional systemic dichotomies as majoritarianism versus proportionalism: outcome of diverse system features – resources and incentives as explanatory mechanisms – preliminary case studies – the limitations of institutional engineering

In a footnote to Chapter 7 of ‘The Open Society and Its Enemies’ Karl Popper describes what he calls the ‘Paradox of Democracy’: the possibility that a majority decides for a tyrant to rule. This is the lesser known paradox of the three to which he pays attention, the other two being the ‘paradox of freedom’ – total freedom leads to suppression of the weak by the strong – and the ‘paradox of tolerance’ – unlimited tolerance leads to the disappearance of tolerance.