Deliberative democracy often presumes that the deliberators are members of a political community who often share common understanding about their values, even when they disagree about them. Participatory planning processes building upon these ideas argue that planning itself has to be communicative among a variety of interest groups and should, usually, result in a common consensus. However, the boundaries of these groups rarely get attention. These boundaries shape not only the discursive practices within groups but also among them, and therefore need to be examined more thoroughly. Furthermore, the relationship of membership to substantive issues of planning is important yet underexplored. Political membership in a diverse, mobile, transient and multicultural world is a contested subject and should be given deserving attention for its implications for planning practice.