Photo-Illustration: Intelligencer; Photos: Getty America is in the midst of an epistemological crisis, one most visible and most urgent in the realms of health and medicine. Issues previously contested at the fringes of politics without clear ideological valence — vaccines and fluoridation, nutrition and the chronic-disease epidemic, whether and how to fund cancer research — have become central to a polarized debate not just about what’s right but about what is real . If the Obama era