 In addition, Williams explains how representatives need to mediate the representative-constituent relationship in order to build “trust.” For Williams, trust is the cornerstone for democratic accountability. Relying on the experiences of African-Americans, Williams shows the consistent patterns of betrayal of African-Americans by privileged white citizens that give them good reason for distrusting white representatives and the institutions themselves. For Williams, relationships of distrust can be “at least partially mended if the disadvantaged group is represented by its own members”(1998, 14). Finally, representation involves mediating how groups are defined. The boundaries of groups according to Williams are partially established by past experiences — what Williams calls “memory.” Having certain shared patterns of marginalization justifies certain institutional mechanisms to guarantee presence.