How does a sudden electoral upset affect the dynamics in the spatial distribution of votes? This article approaches the question in the context of Finnish parliamentary elections in 2007 and 2011 by exploring whether the exceptional success of a nationalist-populist True Finns Party (PS) in 2011 changed some of the fundamentals in the traditional stronghold areas of other parties. A totally new stronghold area did not emerge as the electoral support of PS was geographically extremely evenly distributed. The findings contradict with the conventional wisdom that nationalist-populist parties have a potential clientele on restricted geographic areas. It was tested whether the True Finns dominated areas were characterised by such social structural macro-level characteristics that have typically explained the popularity of radical right populist parties elsewhere in Western Europe. These factors, such as unemployment and a high number of immigrants, did not match the case of True Finns at aggregate level, although the success of PS has been furthered by the same phenomena that have fostered radical right populist parties elsewhere. This article illuminates how PS managed to penetrate into geographically and social structurally in very different kinds of areas. PS had an appeal on the political left, centre and right, which are successful in different kinds of political environments. The ‘big bang victory’ of True Finns was not an earthquake emerging in a certain political landscape, but a political protest throughout Finland. The article shows just how important the national context is in ecological analyses of party support.