The Dutch party system has been in flux since the turn of the century, with the emergence of radical right-wing populist parties in 2002 (the LPF) and 2006 (the PVV), and the transformation towards an ideological space that is structured by both a socio-economic dimension and a cultural dimension (immigration and multiculturalism). This paper aims to understand how these changes have affected coalition politics in the Netherlands both substantially (direction) and strategically (agenda-setting). For that purpose we focus on changes in the configuration of the Dutch party space between 2002 and 2012: the relative ideological positions and strategic positions of political parties. In this paper we combine Schattschneider and Schofield to formulate a spatial model of coalition formation in which the concepts of the core and the heart play a crucial role. Our analyses, based on content analysis of party manifestos between 2002 and 2012, illustrate how the Dutch party system lost its political “core” after 2006, through a combination of electoral fragmentation and ideological drift of the conventional mainstream parties. No single party is able to dominate coalition formation and set the agenda for the subsequent governmental period. This change lays bare the increased instability of in Dutch politics.
