A new political cycle started with the 2012 regional elections in the Basque Country, after armed separatist organization ETA announced the end of its activity in 2011. In the midst of a major economic, social and political crisis in Spain, a new party, Podemos, emerged, shaking up the whole spanish party system and obtaining a remarkable electoral success in the Basque Country, Catalonia and Galicia, all three regions with center-periphery conflicts. While Podemos’ emergence raised considerable attention in political science and sociology in recent years, research on sub-national politics has mostly focused on nationalism, leaving a research gap in the linkage between these two features. This paper examines the impact of a new political party in a ‘polarized pluralism’ party system, divided by the left-right cleavage and the nationalist-centralist one. We provide an insight into Podemos’ electorate in the Basque Country, a complex political context, key in Spain’s multi-level party competition. Using public opinion surveys, the paper maps the main characteristics of the electorate and examines the consequences on this particular party system. The empirical analysis relies on a pooled dataset of the 2017 pre- and post-electoral surveys carried out by the Centro de Investigaciones Sociológicas during the regional elections in the Basque Country. We suggest that electoral behavior of younger generations is changing, with a different attitude towards nationalism and the underlying political conflict. Our results confirm findings in previous research on Podemos’ electorate, but point out the importance of the decentralization issue in the basque country. More precisely, we find that newer generations of voters are less attached to nationalism and support decentralization as a democratic issue and a differentiated cultural identity. Finally, the findings raise the question of the evolution of the center-periphery cleavage during the Great Economic Recession, which shall be explored in a comparative approach in further research.< Leer menos