The paper examines the legal developments associated with new Hungarian Constitution, a text that, by entrenching the normative convictions and institutional solutions favored by a contingent political majority, gives rise to a distinct institutional setting: the ‘partisan constitution’. The analysis unfolds in three stages. Firstly, the new Hungarian Constitution is contrasted with the idea of pluralist constitution traditionally inspiring national European constitutions. Secondly, by investigating the reactions of European institutions to the approval and implementation of the partisan constitution, the difficulties in affirming EU values post enlargement are discussed. Finally, the Hungarian Constitution is assessed also in the light of the prevailing contemporary EU legal culture. It is argued that the Hungarian Constitution reproduces in amplified and grotesque form a more profound and pervasive phenomenon: the corrosion of European constitutional culture. Thus, rather than looking at it as a backward product and a contingent malaise, we should study and criticize it as the most emblematical example of a broader trend: the decline of the idea of pluralist constitution.