While think tanks are a global phenomenon, their role in shaping US policy offers an instructive example of think tank influence on policymaking due to the immensity of resources directed towards those ends, with education policy serving as a prime example. Focusing on a distinct set of "incentivist" education policies, this analysis describes the think tank-philanthropy linkage in US education policymaking. We offer examples of how philanthropists provide financial, empirical and political resources to advance think tanks' policy ideas through advocacy networks; describe the multiple functions performed through advocacy networks of intermediary organisations, noting the diffusion of form and function around tasks such as knowledge production, political and media support; and we highlight the ways in which US venture philanthropists and think tanks connect around "idea orchestration" in order to advance ideas in policy processes. We suggest that, especially in the realm of incentivist policies, think tanks do not appear to produce or incubate but rather promote ideas, and actually often only a single idea. The concluding discussion considers advantages evident in idea orchestration and the implications of private control of public policymaking.