This article suggests that Jacques Derrida’s deconstructive theory of pure forgiveness of the unforgivable is a persuasive philosophical concept that nonetheless breaks down at the moment when it enters into a political discourse. Tracing two conflicting strains within Derrida’s theory–the deconstructive rejection of ideas’ degrading circulation and the unabashed endorsement of Nelson Mandela’s engagement of the ideals of democracy and justice–this immanent critique will point to possibilities for Derrida’s theory of forgiveness to have political relevance. It begins with an exploration of the philosopher’s theory of pure forgiveness as an aporia of the impossible forgiveness of unforgivable crimes. It then reveals tensions between Derrida’s deconstructive resistance to what he sees as the economic exchange of forgiveness and his uncritical endorsement of Mandela’s political use of the ideals of justice, freedom, and equality. This critique hopes to allow for new engagements with Derrida’s thought that will allow political and critical theory to address forgiveness as an important factor in postconflict politics and everyday life.