Résumé
This paper offers an explanation to the vote at the 2011 primary elections which have designed Francois Hollande as the candidate of the French socialist party for the presidential election of 2012. Our goal is to put into question the nature and the electoral effects of this kind of democratic mobilization -for an election opened to all the French citizens who were sympathizers of the socialist party. Our demonstration is based on an exit polls survey driven in Montpellier and on a quantitative analysis of electoral and sociological data for all the polling stations of the city. Our results putt the lights on the censual logics of this election - that imply a limitation of its democratic significance - and the role of the partisan structures in the framing of the mobilization and the orientation of vote. Adapted from the source document.