Since Antiquity, the rhetorical anaphora is a well-known argumentative device, but its contours are often vague and imprecise. In this paper, we will use a conceptual tool, the "motif" as well as a statistical tool, the test of Lafon, to provide a more precise definition of the rhetorical anaphora and to transform it into an observable linguistic phenomenon allowing automatic identification and quantitative treatments. Our demonstration will lean on examples mined, on the one hand, out of the literary classical Latin texts of the LASLA and, on the other hand, out of Nicolas Sarkozy's campaign speeches during the 2007 presidential election.