Students of political change focus mainly on the transitions from non democratic regimes to democratic ones, and vice versa. Much less attention is devoted to the transitions within the same type of regime, in particular the political change of democratic regimes. When, why and how do democratic regimes change? Pietro Grilli di Cortona dealt with this topic in an article written in the turmoil of the Italian transition from the First to the so-called Second Republic (Grilli di Cortona 1995) and in a book published ten years later (Grilli di Cortona 2007) when the Italian endless transition was still open.
In these two pieces Pietro Grilli takes into consideration various aspects of this type of transitions. From a theoretical point of view, he distinguishes between the changes of genus, when the type (democratic, authoritarian, totalitarian) of regime is involved (inter-regime transitions), and the changes of species when the regime remains the same but some of its important traits are transformed (intra-regime transitions). He also underlines that this second type of changes are much rarer in democratic regimes than in non democratic ones. And, as we shall see below, this is due to a specific characteristic of democracies. From a historical point of view, Grilli analyses the Italian case and its various institutional reforms from the Legge Acerbo (1923) up to the recent electoral and constitutional ones. Thirdly, in a comparative perspective Grilli contrasts the Italian transition (from 1993 up to nowadays) with the French (1958-1962) and the Belgian (1962-1993) ones. In the light of this comparison he proposes in the last chapter of his book an interpretative model of change within democratic regimes.