DescriptionThe Eastern enlargement of the EU represented a historic moment in breaking the East-West divide. EU membership (the international dimension of democratization) was expected to contribute to the consolidation of democracy in the Central and Eastern Europe (CEE). However, post-EU accession, a number of cases have been plagued with democratic crisis and in some cases even democratic regression. While another group of cases have become stable consolidated democracies. Current literature has been unable to provide an explanation for this variant outcome as the international dimension of democratization remains an under-theorized research program. In light of the theoretical gap in understanding the conditions under which the promotion of democracy by the EU is likely to be effective, this study asks: How can the variations in post-accession CEE be explained? This study argues that, those CEE states that are experiencing the strongest cases of democratic regression are the same states that exhibited the strongest majoritarian institutional designs during the pre-accession period. Yet, because the democratic regression that is being experienced in CEE began during the post-EU accession period, it is the argument of this study that the rigid pre-accession process was more conducive to democratic consolidation in those states exhibiting stronger consensual institutional designs than those exhibiting stronger majoritarian institutional designs. In order to test this hypothesis, this study adopted a mixed methodological approach. On the one hand, the study analyzed cross-sectional time-series data in order to test for the statistical significance of the proposed hypothesis. On the other hand, the study utilized a most-similar research design through a comparative analysis of six case studies. The purpose of the case studies was to elucidate the theoretical hypothesis described above, and to better understand the causal mechanisms of the proposed relationship between the variables of interest. The findings were able to confirm the hypothesis by showing that due to the more robust nature of political competition under consensual democracies, European integration proved beneficial to democratic consolidation, compared to the more limited form of political competition under more majoritarian designs.