This article addresses concerns that the growth in global governance may be bringing with it a decline in the significance of democratic sources of political legitimacy. One approach in evaluating such concerns is to ask whether the respective patterns of legitimation for private and public authority differ or whether they refer to a similar set of normative standards. Private transnational governance regimes provide useful contexts in which to assess the presumed democratic erosion. They seem, almost of themselves, to make the case for such a decline: in them regulatory authority is exercised by non-state actors who, by their very nature, lack the kind of authorization afforded by the democratic procedures that legitimize state-based regulation; in addition, they are intrinsically linked to the notion of politics as a form of problem-solving rather than as the exercise of power. Given these characteristics, when governance arrangements of this kind are subjected to criticism, one would expect justificatory responses to relate primarily to performance, with normative criteria such as fundamental individual rights and the imperative for democratic procedure playing only a minor role. On the basis of a qualitative content analysis, the study tests three ideal-type patterns of legitimation for plausibility. The case selected for examination is the recent controversy surrounding the hybrid governance regime that operates to prevent the use of performance-enhancing drugs in sport. The debate offers the possibility of a 'nutshell' comparison of the respective patterns of legitimation used in criticizing and justifying state and non-state regulatory authority. This comparison yields two findings. The first is that the values used to appraise the state-based components of the sporting world's hybrid regulatory regime do not differ systematically from those used to appraise the private elements: contestation and justification in both cases are founded on normative criteria relating to fundamental individual rights and democratic procedure and not just on performance-related considerations. The second finding is that justificatory grounds of the first type do not appear to be diminishing in importance vis-a-is those of the second.