This paper aims to present possible explanations as to why radical right-wing populist parties have been highly successful in Denmark but have largely failed in Sweden. It shows that Denmark and Sweden shared several important opportunity structures, in particular related to anti-immigrant sentiments among the electorates and feelings of disenchantment toward the political institutions, but also that the two countries diverged in some important ways: First, while the socioeconomic cleavage dimension lost much of its importance in Danish politics, it was still highly salient in Swedish politics. Secondly and related, the issue of immigration has been much more politicized in Denmark than in Sweden. While immigration has dominated the political agenda in Danish politics during the last decade, in Sweden the socioeconomic dimension has taken center stage.