While some types of democracy can sustain ethnic and cultural diversity, others can clearly undermine it. In The Dark Side of Democracy, Michael Mann argues that extreme crimes like genocide and ethnic cleansing tend to occur, or at least be legitimized, within a majoritarian democracy framework. This article broadens Mann's approach in two directions: first, it confirms that majoritarian democracy in plural societies can provide the pre-existing institutional context where conflict, nationalism and exclusion can thrive, eventually degenerating into self-destruction. Second, it focuses on the tendency by some governments to turn to patriotism and populism as sources of legitimacy at a time when the latter appears to be crumbling. In addition, the article questions both the ‘democratic peace’ and the ‘failed democratization’ approaches for their reliance on an ideal type and fixed notion of democracy, arguing that the latter has been weakened by neoliberal globalization, particularly as it interacts with the legacy of pre-existing forms of majoritarianism. The article concludes that these forces need to be studied simultaneously in order to have a broader picture of the contemporary weakening of democratic practices and institutions within some nation-states.