Résumé : Examining the political implications of Social Media, the paper will evaluate how, for the first time in French politics, Social Media may have induced the election’s course and possibly it’s outcome between Ségolène Royal and Nicolas Sarkozy during the 2007 Presidential Campaign. The paper examines how political parties have taken advantage of Social Media to foster new allegiances and bridge a gap in their already existing communication strategies and furthermore, how Social Media helped candidates gain considerable recognition, launching an unprecedented support wave. The paper thereby underscores how Social Media fostered the emergence of a new type of ‘agenda setting dynamic’ during the campaign, based on the notion of ‘two-step flow’. In parallel, the paper argues that the increased weight of Social Media in the campaign may have cleared up areas of judgement in which political ideas could have been questioned and criticised.