Prior to WW II, the American government played a relatively small role in the support of science, especially outside of its own institutions. That situation changed dramatically with the war and the Cold War that followed. We explore how these events transformed the role of science in American life, vastly enhancing the prestige of scientists, and shaping the extent and the nature of federal involvement in science. These and later developments, including the commercialization of academic research, raise important questions about the appropriate role of science and scientists in a democracy. In particular: How can we reconcile the need for scientific and technological expertise on the one hand, and for the democratic control of science on the other? We consider different theoretical approaches to this issue, and illustrate the dilemmas it poses with a number of empirical examples.