Contemporary foreign aid discourses position program evaluation as the objective source of scientific knowledge about “what works” in global development, and evaluators as the expert arbiters of this truth. Such narratives suggest a well-oiled rationality in foreign aid, but obscure how politics, power and ideology shape evaluation practices and uses. As growing numbers of evaluators from groups at the peripheries of power navigate the social and epistemological hierarchies that structure their field, they practice overt politics, covert infra-politics, and emergent extra-politics in an art of making do. The stories we tell (and don’t tell) about these dynamics at the heart of global development evaluation have the capacity to shape what is known, knowable, and worth knowing about the field. And yet evaluators have been largely ignored by critical science and movement scholars to date. In this dissertation, I ask how three structurally subaltern groups of evaluators understand and engage the politics of their profession: those at the steep start of their careers, those from countries in the Global South, and those committed to feminist agendas of social transformation. Through participant observation of evaluation association meetings, and through document analysis of publications and online forums, my study reveals a profession bound in many ways to prevailing power structures, that is nonetheless increasingly called to “speak truth to power.” Its most marginalized members must tread carefully, when the authority that gets them hired relies on truth-telling that can get them fired, and when challenging knowledge hierarchies destabilizes the profession that sustains them. And yet, I show that their mere presence and situated practices – whether consciously political or unconsciously disruptive – can cause friction that shapes the trajectory of the field. Constrained by the development enterprise’s bureaucratic rationality and liberal discourses of equity, dominant power in the evaluation field moves, amoeba-like, to incorporate reform agendas, even if in modified or diluted form. While this absorptive action can pacify protest, it also changes the content of hegemonic discourses. My findings modify theories of contentious politics, by illuminating interacting mechanisms by which evaluation politics can both reflect and redirect the power relations that govern international development.