This article examines the rise in the number of court cases related to discrimination against trade union workers in France since the late 1990s. It identifies the sources of support for victims of discrimination that allow them to file complaints in court. The judicialization of union-related cases of discrimination has been made possible by a new discourse linking the recognition of individual merit to the common cause of re-unionizing. Developing a special method of bringing evidence and the specialization of certain union actors and lawyers have helped make legal action against discrimination routine. But the historical roots of this strategy leave the question open as to how it can be applied to workers in secondary labor markets, particularly precarious workers.