In the absence of effective national and intergovernmental regulation to ameliorate global environmental and social problems, “private” alternatives have proliferated, including self-regulation, corporate social responsibility, and public–private partnerships. Of the alternatives, “non-state market driven” (NSMD) governance systems deserve greater attention because they offer the strongest regulation and potential to socially embed global markets. NSMD systems encourage compliance by recognizing and tracking, along the market’s supply chain, responsibly produced goods and services. They aim to establish “political legitimacy” whereby firms, social actors, and stakeholders are united into a community that accepts “shared rule as appropriate and justified.” Drawing inductively on evidence from a range of NSMD systems, and deductively on theories of institutions and learning, we develop an analytical framework and a preliminary set of causal propositions to explicate whether and how political legitimacy might be achieved. The framework corrects the existing literature’s inattention to the conditioning effects of global social structure, and its tendency to treat actor evaluations of NSMD systems as static and strategic. It identifies a three-phase process through which NSMD systems might gain political legitimacy. It posits that a “logic of consequences” alone cannot explain actor evaluations: the explanation requires greater reference to a “logic of appropriateness” as systems progress through the phases. The framework aims to guide future empirical work to assess the potential of NSMD systems to socially embed global markets.