Summary - In a climate of open debates about the institutional reforms in Italy it is important to bear in mind the constitutional experience of the French Republic for an adequate reflection on the rôle which the institutions and in particular the Presidency of the republic had in bringing about the rising of a system of parties able to guarantee a good level of governability. The singularity of the French case has to be traced, as a matter, in the capacity proved by the system to react against degenerations of the parliamentarism of the IV Republic. With the advent of the V Republic, at the same time as strong institutions, balanced by the drawing power of a President of the Republic of undoubted prominence, comes out a new bipolarized system of political parties, with a clear identification between Right and Left, that for the first time ammows the constitution of stable governments. The high correlation between a partitic regime that, thanks to the inputs created by the institutions themselves, reorganizes itself from top to bottom, and a form of government with a strong presidential characterization, is the fundamental aspect to bear in mind in the analysis of the V Republic.

From the year 1962 we witness the presidentalization of the system. Relying on the support of a large majority in the Assembly, of the Right till 1981, of the Left from 1981 till 1986, all the Presidents from De Gaulle to Mitterrand contribute to a substantial continuity of regime in which the Presidency of the Republic remains the master key of the French political-institutional system. The political parties although increasing attributions and influence within the institutions, do not succeed in changing the substantial relation of subordination that binds them to the Presidency of the Republic. The preponderance of the institutional factor, a fundamentally positive fact, appears still evident during the " cohabitation " from ‘86 to ‘88 and with the period of " ouverture " inaugurated from 1988. The non-agreement between presidential and parliamentary majority from 1986 to 1988, and the formation of a coalitional Centre-Left government in 1988, in a context of decomposition of the traditional parties alliances, far from representing the end of the stability, points out once again the importance of the presidential function.