Public health must engage the social, political, and economic foundations that determine population health (Box 1). The conditions that make people healthy often are outside what have historically been considered the remit of the health professions: health improvement now requires participation in politics and social structures. Such engagement is much more perilous than traditional efforts to maintain population health such as sanitation, food safety, and response to epidemics. Operationally, engaging issues such as racial segregation in housing and education requires clarity of advocacy by the public health professionals who must, to be effective, work with media, business, and academia, as well as in the governmental public health infrastructure. This will require a boldness on the part of public health, and the reliance on agents of public health action, such as universities, that are less beholden to political pressures in establishing their budgets and their educational and research agendas.