This chapter examines how the political context impacts the use of behavioural insights in public policy. Specifically, we explore how the political context, which frames the use of nudges in matters of public health, has led to a mismatch between policy intent and implementation. This problem of mismatch is explored through two examples: health promotion and organ donation. In the first example, it is suggested that behavioural health promotion focuses too much on individual lifestyle preferences, with insufficient account being taken of the wider social determinants of health. The example of organ donation is used to show that the nudges may be an inadequate tool for addressing complex public policy problems. Drawing on such examples, the chapter concludes with a consideration of how this mismatch impacts upon broader questions concerning evidence-based policy and political legitimacy.