The European Court of Human Rights invokes consensus primarily to identify a threshold for extending the margin of appreciation or, conversely, reserving substantive interpretative authority at central judicial level. In that context, consensus is a determinant of the relevant law. In contrast, for European Union (EU) citizenship law, consensus arguably presents a challenge to how rights are protected. Citizenship case law on the conditions governing access to social benefits is used as an illustration of legal change with consequences of rights retraction to investigate the legal considerations that should apply in such situations. Irrespective of what specific rights are being looked at, or whether in European Convention on Human Rights or EU law, there is a shared challenge: how to manage fundamental questioning of and uncertainty around the purpose of institutions beyond the State? In the project of shaping rights over time, an important theme therefore bonds the work of the Strasbourg and Luxembourg courts; it is no easy task to determine when consensus amounts to the exercise of leadership, on the one hand, or to its abrogation, on the other. However, it is also argued that consensus is not the appropriate tool to resolve this critical question.