We explore the impact of prosocial orientations on a domain of American public opinion that has puzzled many-attitudes toward social welfare policies. We focus on the orientation of humanitarianism, i.e., a sense of obligation to help those in need, and find that this value can explain support for a wide variety of social welfare policies. We argue that humanitarianism is an important element of the American sociopolitical ethos, although it has received little attention in the public opinion literature. We contrast humanitarianism with egalitarianism and show that these dispositions lead people to support distinctive sets of policies that constitute different types of welfare state. While egalitarianism causes people to embrace policies that mandate an extensive economic role for the government, humanitarianism is associated with more modest policies that seek to address the problems of the needy. Support for these more modest policies has generally been much greater in the United States than support for more invasive policies that seek to tinker with the free market. Thus, we argue that humanitarianism provides a better explanation for public opinion toward welfare in the United States than egalitarianism. We discuss the implications of these findings for public opinion research.