This paper interrogates certain contractarian theoretical presumptions concerning the development and maintenance of political constitutions. Specifically, the extent to which constitutional agreement is said to be inclusive of all persons affected by the activation of proposed provisions, and the extent to which such provisions remain agreeable, is critically appraised. For example, rectifying historical exclusions of indigenous peoples from constitutional agreement procedures, and the constitutional accommodation of demands for racial equality and recognition of indigenous rights, presents as an important motivation for constitutional change in actually existing societies. The objective of this paper is to interpret constitutional developments on matters of indigenous rights as the manifestation of complex, adaptive arrangements, instituted by actions seeking to restructure political rules and reframe the boundaries of permissible political action. Taking the Australian case, this paper illustrates how acts of constitutional entrepreneurship by indigenous groups have contributed to constitutional changes such as racially non-discriminatory treatment and recognition of indigenous governance. Entrepreneurship is seen as a part of broader endogenous processes reshaping constitutions, including constitutional arbitrage by activists between legislatures and judiciaries, and mobilizing popular support for indigenous rights. The framework presented in this paper extends constitutional political economy insights regarding the evolution of basic political institutions.