A challenge for the identification of the core components of a beliefs system is the topological examination of these components within the overall structure of the said system. By modeling beliefs as nodes of interconnected networks, this research investigated the centrality of adherence to populist ideology and classical ideological attitudes in relation to voting behavior and negative feelings toward immigrants. Data from a sample of 774 Italian adults were examined by means of three Network Analysis models. Results showed four constitutive dimensions of populist ideology: People Sovereignty, Anti-elitism, People Homogeneity, and Manichaeism. The dimensions of Anti-elitism, People Sovereignty and Homogeneity were found to be the core. Analyses also highlighted the centrality of right-wing authoritarianism (RWA) and social dominance orientation (SDO) within the broader beliefs system, including voting, populist ideology dimensions, and anti-immigration. RWA was positively related to the core of populist ideology, whilst SDO was negatively associated with or unrelated to it. However, both RWA and SDO exceeded populist dimensions when associated with populist right-wing voting, representing the unique intermediate links in connecting it with anti-immigration. Five Star Movement voting emerged as a purer form of populist support, relating directly only to populist dimensions and placing itself at a greater distance from ideological attitudes and anti-immigration.