ABSTRACT Although compliance with constitutions is undoubtedly one of the most essential topics in the current public debate, there are still a lot of questions about its determinants that have to be addressed. What is the impact of the populistic and anti-pluralistic character of ruling political parties on constitutional compliance of the government and does it depend on how long such parties have been in power? In our study, based on data for 147 countries during the period between 1990 and 2019, we aim to investigate the relationships between populism, anti-pluralism, and constitutional compliance, with a special focus on the years of the populist or anti-pluralistic ruling parties in office. In a series of panel regressions, we find that the longer anti-pluralists remain in power, the worse the effect they may have on constitutional compliance of the government. These results suggest that the respect for a constitution shown by government representatives is dependent on the nature of the party from which they originate and that anti-pluralism entrenched in the political scene for many years can be a real peril.