Government-sponsored health insurance is a central pillar of the modern welfare state. In advanced industrial democracies, public spending on medical care accounts for an average of 6 percent of gross domestic product (GDP), making it the largest category of social spending after public pensions.Computed from Organization for Economic Cooperation and Development, The Reform of Health Care Systems: A Review of Seventeen OECD Countries (Paris: Organization for Economic Cooperation and Development, 1994), 38. The comparison with pensions is made by Karl Hinrichs, “The Impact of German Health Insurance Reforms on Redistribution and the Culture of Solidarity,” Journal of Health Politics, Policy and Law 20 (1996): 653–87. Despite the popularity and resilience of established health programs, however, the introduction of government-sponsored health coverage has been highly controversial everywhere. Few social programs involve the state so directly in the workings of the economy and the practice of a powerful profession. Few entangle the interests of so many diverse and resourceful groups. And few cast in such stark relief the ideological principles at stake. Although the participants in conflicts over health policy have differed from nation to nation, no country has acquired national health insurance without a fierce and bitter political fight.