 He was elected senator during the senatorials of 1986.At the Reims Congress, in September 2008, the political current ""Trait d'union"", created after the victory of the "No" in the French European Constitution referendum of 2005, Mélenchon made a new contribution.On the eve of the filing of the motions, an agreement was reached between the seven contributions of the left wing of the PS, and Jean-Luc Mélenchon was one of the signatories of the motion C entitled "A world of advance", led by Benoît Hamon.