Incorporated in the debates about activism transformations, this article discusses the historical separation of the two main models defined by Jacques Ion. The purpose is to highlight the plurality of militant practices at any time and the diversity of relationships between actors and commitment models. The investigation is based on observations and interviews with former communist party members who lead a People’s University in the old Paris Red Belt. The diachronic analysis of militant careers and interactions in the civic association context shows the tensions between activism representations and observable practices in the organizations. From these results, we propose a sociohistorical perspective emphasising the plurality of commitment models and militant practices.