There is increasing recognition in the health promotion and population health fields that the primary determinants of health lay outside the health care and behavioural risk arenas. Many of these factors involve public policy decisions made by governments that influence the distribution of income, degree of social security, and quality and availability of education, food, and housing, among others. These non-medical and non-lifestyle factors have come to be known as the social determinants of health. In many nations--and this is especially the case in North America--recent policy decisions are undermining these social determinants of health. A political economy analysis of the forces supporting as well as threatening the welfare state is offered as a means of both understanding these policy decisions and advancing the health promotion and population health agendas. The building blocks of social democracies--the political systems that seem most amenable to securing the social determinants of health--are identified as key to promoting health. Health promoters and population health researchers need to "get political" and recognize the importance of political and social action in support of health.