The paper proposes an explanation of the different configurations and results of the social mobilizations of the so-called Arab Spring in three Maghreb countries: Morocco, Tunisia, and Libya. From a comparative perspective, we propose the consideration of the power structure (power regime) to complement the analyses focused on the political system in the analysis of the popular revolts. The research is based on over fifty field interviews with policy-makers and social activists conducted during the period 2013-2019, as well as analysis of primary (speeches, press, social networks) and secondary sources. The three cases chosen correspond to three different typologies of power regime according to the greater or lesser concentration of primary elites, and to the capacity to control different resources (state, capital, coercion, information, ideology, etc.). Our starting hypothesis is that in a dynamic of social mobilization, the structure of the power regime directly influences both the type of response of the regime (strategy) and its possibility of survival (control of resources and capacities), as well as the structure of opportunities and the configuration and dynamics of the social mobilization. Of the three models, the type of power regime in Morocco, concentrated elites but diversified resources, appears to be particularly resistant to changes and threats. On the one hand, the elites, being concentrated and homogeneous, have a great resilience; by accumulating power through diverse resources, they have negotiation capacity if they are forced to make some concessions, and the capacity to use coercion if necessary. In the case of Libya, a power regime with concentrated elites and resources during the rule of Muammar Al-Qhadafi, the response to the mass protests was highly repressive as the primary elites had little negotiating capacity. In this case, the concentration of power resources in a rentier state (state and hydrocarbon sector) left them little room to make partial concessions. With respect to Tunisia, a power regime with diversified elites and resources during the Ben Ali presidency, when social mobilization became widespread, a sector of the primary elites controlling resources other than the state along with other secondary elites considered the possibility to gain power with the fall of the elites governing the political regime, or they could be dragged into losing power with the instability.