Constitutional theory is in flux. Deep seated transformations in the relations between national and transnational forms of social ordering as well as between the public and private dimensions of society has challenged the basic assumptions which constitutional theory has relied on throughout modern times. On this background three core arguments are presented and examined: First, on the basis of a historical perspective it is argued that the transformations which have become visible in recent decades are in fact the result of incremental structural changes which have unfolded since the late 19th century. Second, a case is made for an integrative theory of constitutionalism capable of bridging the national/transnational and public/private distinctions. Third, the move towards an integrative theory implies a need to rethink our understanding of what a constitutional object as well as a constitutional subject is.