Abstract
Why did democratic backsliding reach fundamentally different depths in Hungary and Poland, two states that shared comparable institutional legacies, European Union membership and right-wing populist governments? This article argues that existing comparative accounts – centred on executive aggrandisement and electoral authoritarianism – are insufficient to explain this variation, because they overlook the decisive role of constitutional design and the specific legal strategy adopted by each governing party. Drawing on a novel analytical synthesis of 'abusive constitutionalism', 'legal populism' and 'stealth authoritarianism', the article demonstrates that Hungary's supermajority enabled a comprehensive constitutional overhaul that irreversibly restructured the conditions of political competition, whilst Poland's institutional architecture and fragmented opposition preserved sufficient democratic resilience to allow electoral reversal in 2023. The article further engages V-Dem longitudinal data (2010–2024) to trace the divergent trajectories empirically, and evaluates the EU's rule-of-law enforcement evolution across three phases: rhetorical condemnation, Article 7 proceedings and financial conditionality. The findings advance a 'constitutional threshold' theory of backsliding depth, with implications for comparative democratisation and EU institutional design.