The Catholic Church is the most ancient institution in the world and, ever since the time of Emperor Constantine, it has been engaged with politics in order to affirm its values and defend its interests, fully aware of the strength stemming from its identity, and autonomous from every other power, while it guided the values and behavior of great masses of people. The Catholic Church is hierarchically organized as a multiform ensemble of organizations which make its structure almost unique, its leadership being centralized in the Pope and in his College of Cardinals, and relies on a worldwide organization and membership. Its bureaucracy is clearly identifiable and its hierarchic leadership, either at the international level or in any national political system on the holy Scripture and on the obedience by the faithful. Given such institutional features, the Catholic Church appears as a strategic actor, both in national and global politics (Hertzke, 2009), able to act like a strong interest group aiming to influence both politics and policies on several grounds (Ferrari, 2006). As an interest group, the Catholic Church is atypical, insofar as it hybridizes the features of several kinds of groups (Segers, 1995): institutional group, public group, and membershipbased group: (a) as a hierarchical organization, the Catholic Church can be identified as an institutional group safeguarding traditional theological teachings and defending those economic interests focused on preserving and maintaining the organization itself; (b) furthermore, the Catholic Church can be identified as a public interest group pursuing public good not only for its members but for the society as a whole; (c) finally, the Catholic Church can be identified as a membership-based group, insofar as it represents a worldwide grouping of the faithful.