This article investigates the possibilities for promoting and implementing a more progressive or essentially social democratic political and constitutional agenda within the existing institutional and constitutional constraints of federalism. Although this question has been a long debated and much discussed one in social democratic political and constitutional theory, this article seeks, indeed, to bring new light to this (traditional social democratic) perspective by emphasising the potential advantages of federal theory and the federal structure for a developing and contemporary social democratic agenda. Particular attention is devoted to the progressive possibilities which inhere in the States and their accompanying (State) constitutions and the consequent potential which State constitutionalism has to support a renewed and more distinctively progressive political (and constitutional) practice. The presence, at this time, of a conservative federal government and Labor governments in all of the States indicates an important need for theorists on the Left to re-evaluate the efficacy of the States in promoting a more progressive agenda and to reassess the extent to which the 'dual' character of federalism may, in fact, be facilitative of essentially social democratic objectives.