The present research intends to shed light on the processes enabling political minorities to transition into normatively acceptable groups, by investigating how a previously marginalised far‐right movement (the French National Front) is progressively becoming mainstream. Drawing on the social representations approach, we argue that perceived social norms play a pivotal role in this process. Using a longitudinal and experimental design, the study (N = 233) was implemented in the ecological context of the 2012 French presidential election at a Parisian university campus, a traditional anti‐far‐right bastion. We tested whether the electoral campaign altered the perceptions of social norms, whether the perceived social norms were easily malleable in this specific context and, most important, whether they influenced people's willingness to speak out in public against the far‐right movement. The findings support affirmative answers to all three questions. We conclude that, in periods of collective uncertainty, changing perceptions of social norms might play an important role in the weakening of public opposition to far‐right movements. This, in turn, helps to explain the recent transition to mainstream recognition of a number of previously marginalised political movements in Europe and around the globe.