This paper focuses on Sartori's concept of anti-system party and its utility for understanding contemporary politics. After outlining the classical definitions and their main misconceptions found in the literature, it highlights the chal-lenges posed to the analytical power of Sartori's concept by populist parties, which remain ideologically at odds with liberal democracy despite their inte-gration into national governments. The paper underlines the importance of adopting a bidimensional perspective that evaluates both the ideology as well as the behavior of political parties, allowing these dimensions to vary inde-pendently from one another. This approach is essential for fully understanding anti-system politics today.
