Scholars have recognized that contentious political action typically draws on relatively stable scripts for the enactment of claims making. But if such repertoires of political practice are generally reproduced over time, why and how do new modes of practice emerge? Employing a pragmatist perspective on social action, this article argues that change in political repertoires can be usefully understood as a result of situated political innovation—i.e., of the creative recombination of existing practices, through experimentation over time, by interacting political agents (...) for whom old repertoires were proving inadequate to the changing context of action. The utility of this approach is demonstrated by applying it to explain the historical emergence of a new set of populist mobilizing practices in early twentieth-century Peru. The results have implications for the study of political action and historical change. (shrink)