The EU’s enlargement policy has successfully strengthened state institutions in Central and Eastern Europe (CEE), while failing to do so in the Western Balkans (WB). This is often attributed to domestic political factors, or the ineffectiveness of the EU’s political conditionality in the WB, with its detrimental effects on democracy promotion. This paper instead focuses on the EU’s governance of economic integration and its impact on state-society relations in candidate countries. Based on a comparative analysis of EU strategy in Romania and Serbia, the paper argues that differences in the EU’s governance of market integration shape, in diverse ways, candidate states’ ability to extricate themselves from capture by rent-seeking elites and to create new developmental alliances. These differences impact prospects for both development and democracy. Managing developmental consequences of integration and strengthening state institutions should, therefore, be a priority for the EU’s future enlargement to Ukraine and beyond.