Human embryonic stem cell research has generated considerable discussion and debate in bioethics. Bioethical discourse tends to focus on the moral status of the embryo as the central issue, however, and it is unclear how much this reflects broader community values and beliefs related to stem cell research. This paper presents the results of a study which aims to identify and classify the issues and arguments that have arisen in public discourse associated with one prominent policy episode in the United States: the 2004 Californian Stem Cell Research and Cures Initiative (also known as Proposition 71). The findings show that public discourse about Proposition 71 is characterised by a broader range of issues than those usually addressed in scholarly publications and public policy documents. While attention to the moral status of the embryo is an important issue in stem cell research, making it the main focus of public discourse has a polarising effect. This also limits opportunities to identify shared values, understand how political alliances are forged, and develop social consensus. Implications for future research and policy are discussed.