Among the top institutions of our parliamentary system, the Presidency of the Republic is the one which shows most frequently the higher level of institutional formalism, that is a significant gap between its normative basis, thin an ill-defined, and the magnitude of its powes, sometimes so huge that they foster harsh institutional fights. Originally, such formalism was due to the power differentials among the constitutional coalition members, besides the burocratic-organizational resources given to the institution. Systemic factors relating to the competition among parties set the constraints to action and opportunities too, in the medium term, while short term variations in the President power depend on factors such as infra-coalitional tensions. This analysis shows that the judgment on a range of presidential decisions cannot be made only on the basis of law rules. Formal practices are crucial parts of istitutionalization processes, but they have to be discussed on a case by case basis in relation to the various conditions, long and short term, of the political system.