A new form of online citizen participation in government decisionmaking has arisen in the United States (U.S.) under the Obama Administration. “Civic Participation 2.0” attempts to use Web 2.0 information and communication technologies to enable wider civic participation in government policymaking, based on three pillars of open government: transparency, participation, and collaboration. Thus far, the Administration has modeled Civic Participation 2.0 almost exclusively on a universalist/populist Web 2.0 philosophy of participation. In this model, content is created by users, who are enabled to shape the discussion and assess the value of contributions with little information or guidance from government decisionmakers. The authors suggest that this model often produces “participation” unsatisfactory to both government and citizens. The authors propose instead a model of Civic Participation 2.0 rooted in the theory and practice of democratic deliberation. In this model, the goal of civic participation is to reveal the conclusions people reach when they are informed about the issues and have the opportunity and motivation seriously to discuss them. Accordingly, the task of civic participation design is to provide the factual and policy information and the kinds of participation mechanisms that support and encourage this sort of participatory output. Based on the authors' experience with Regulation Room, an experimental online platform for broadening effective civic participation in rulemaking (the process federal agencies use to make new regulations), the authors offer specific suggestions for how designers can strike the balance between ease of engagement and quality of engagement – and so bring new voices into public policymaking processes through participatory outputs that government decisionmakers will value.