Earlier research indicates an increasing popularity of party primaries over the last decades. Used extensively in the US context, the inclusive methods for the selection of party leaders or candidates for public office became appealing for more parties around the world. Following this trend, a few Eastern European parties decided to provide more decision-making power to their members. This process varied greatly across parties: sometimes it was not even mentioned in the statutes, sometimes was mentioned but never implemented, discretionary used, or abandoned after one use. To better understand how these processes function, this paper comparatively analyzes the causes and consequences of primary adoption for candidate selection for the Romanian Social Democratic Party (PSD) and the Slovak Democratic and Christian Union – Democratic Party (SDKU-DS). The two parties differ both in the extent of primary use for the legislative elections (the PSD once in 2004 and the SDKU-DS twice in 2002 and 2010) and in their logic for adoption or primary dynamic. We focus on two main components of primary elections: the features of the internal election processes and their impacts on parties both in terms of internal participation (membership appeal) and structures (leadership - membership relations) and of external electoral performance in subsequent general elections. As both parties used primaries when voting took place on list PR the territorial basis for our analysis is the country level.
