Academic interest in the relationship between populist movements/ parties and constitutions, as well as more broadly in the relationship between forms of populism, illiberalism and authoritarianism, on one hand, and (domestic and international) law and constitutionalism on the other, is rapidly increasing. A significant part of the debate focuses on how to diagnose, and prevent, so-called ‘backsliding’ and on how to save constitutional democracy. There is, in this, much less engagement with the question of how populist movements might equally challenge core dimensions of taken-for-granted notions of constitutionalism and how they might reveal problematic dimensions.
The general approach, often inspired by political science, towards populism argues that it displays a friend – enemy logic in its political mobilisation of ordinary citizens; engages in the construction of a unified people; and criticises the liberal-democratic status quo in the people's name. Most analyses stress a strong tension between constitutional democracy and populism and understand the relationship predominantly as one in which the latter challenges and undermines the former. There is, however, relatively little attention paid to the critical potential of populism, not least in the way the populist challenge might expose problematic dimensions of liberal constitutional democracy. In other words, the selfreflexive dimension of the populist challenge is not taken up.
The most prominent constitutional challenge posed by populism lies in its constituent thrust, that is, the propensity in many populist projects to significantly alter the constitutional order, generally understood as grounded in a form of ’ liberal legalism ‘, into an alternative order, referred to as ’ illiberal democracy ‘, resulting from a conservative ‘moral revolution‘. A not frequently discussed, albeit crucial, dimension of the relation between populism and constitutionalism therefore regards populism's questioning of the fundamental 'spirit’ of the liberal-democratic order. Studies on populism tend to overlook that the ’ invocation of “the people” is not only a matter of bolstering mere political discourse, but of constitutional politics addressing the higher-ranking dimension of the legal and political community, the distribution of powers, and the overall design of rulemaking and application’.