This article demonstrates how EU member states' distinct constitutional traditions shape the impact of EU juridification on national welfare states and social rights. These traditions come with different 'constitutional social rights norms'that is, distinct distributions of obligation and power to protect social rights between judicial and political actors. The article argues that norms common to the political constitutional tradition are less compatible with the EU's juridified notion of rights than those distinguishing legal constitutionalism. To develop this argument, the article takes an in-depth look at Germany and Sweden, which represent the two constitutional traditions. This reveals how the Swedish constitutional understanding of social rights as politically defined collective rights has shifted towards a more juridified notion of rights, as EU law effectively makes social entitlements defined in national legislation more justiciable. The already significantly juridified understanding of social rights in Germany, in contrast, comes closer to that of the EU.