This paper proposes a political economy approach of social conflict, institutional change and crises based on the diversity of perceived interests among social groups. The multidimensional conflict includes ideology, (formal) institutions, and politics. Each of these dimensions corresponds to a relatively autonomous sphere, which has its own logic of functioning. Social groups may be in a dominant or dominated position in one or the other dimension, and the nature of social conflict reflects the differences in positions of the various social groups in these dimensions. Political stability hinges on the existence of a dominant social bloc., i.e. a social alliance supporting the ruling political actors. The implementation of (formal) institutional change by these political actors is driven by the search for such a support. Crisis situations correspond the rupture of the dominant social bloc. Attempts to emerge from the crisis with the reconstitution of a dominant social bloc will have more or less chance of success depending on the possibility of finding a political strategy that can make the expectations of social groups with different perceived interests compatible. Using examples from the French economic and political situation in recent decades, we show how the proposed analytical framework can inform the study of institutional change in situations of social crisis.