Two forum types have featured prominently in deliberative practice: (1) forums involving partisans (such as key 'stakeholders') and (2) forums involving non-partisans (such as 'lay citizens'). Drawing on deliberative theory and cases from Germany, we explore the relative merits of these forum types in terms of deliberative capacity, legitimacy and political impact. The two types offer deliberative governance something different. Non-partisan forums such as citizens' juries or consensus conferences rate favorably in deliberative capacity, but can fall short when it comes to external legitimacy and policy impact. Contrary to expectations, partisan forums can also encounter substantial legitimation and impact problems. How can designed forums contribute to deliberative democratization, given that partisanship is an inevitable fact of politics? We offer some suggestions about how deliberative theory and practice might better accommodate the reality of partisanship, while securing benefits revealed in non-partisan forums.