Social media have the potential to revolutionize discourse between American citizens and their governments. At present, however, the U.S. Supreme Court's public forum jurisprudence frustrates rather than fosters that potential. This article navigates the notoriously complex body of public forum doctrine to provide guidance for those who must develop or administer government-sponsored social media, or adjudicate First Amendment questions concerning them. Next, the article marks out a new path for public forum doctrine that will allow it to realize the potential of Web 2.0 technologies to enhance democratic discourse between the governors and the governed. Along the way, this article diagnoses critical doctrinal and conceptual flaws that block this path. Relying on insights gleaned from communications theory, the article critiques the linear model underlying public forum jurisprudence and offers an alternative. This alternative model will enable courts to adapt First Amendment doctrines to social media forums in ways that further public discourse. Applying the model, the article contends that courts should presume government actors have created public forums whenever they establish interactive social media sites. Nevertheless, to encourage forum creation, governments must retain some power to filter their social media sites to remove profane, defamatory, or abusive speech targeted at private individuals. Although some will contend that ceding editorial control is no more necessary in social media than in physical forums, the characteristic "disorders" of online discourse, and particularly the prevalence of anonymous speech, justify taking this path.