If we agree that, when it comes to morally sensitive issues such as homosexual partnerships or, more generally, claims to recognize other family-pattern, Catholicism makes a difference, then the following might wonder: Why did the Spanish government 2005 successfully implement a Civil marriage law against the massive protests of the Catholic church, while similar attempts failed in Poland (so far, a new law has been debating since recently) and in Italy - all three Catholic states with a dominant Catholic Church? This paper will shed some light on this puzzle while giving insights into political struggles around this conflict and the extent to which Catholic actors and political decision-makers formed informal alliances. An overall answer to the initial question is that much depends on the likelihood of political elites to risk a conflict with the Catholic Church. Here, it is important, whether historically Church-state-relations were and are rather shaped by a “culture of cooperation” or a “culture of conflict”, as it was the case in Spain.