The last few decades witnessed a dramatic change in public opinion towards gay people. This paper uses a difference-in-difference empirical strategy to investigate the hypothesis that the AIDS epidemic and the ensuing endogenous political process led to this transformation. We show that the process of change was discontinuous over time and show suggestive evidence that the '92 presidential election followed by the "don't ask, don't tell" debate led to a change in attitudes. In accordance with our hypothesis, this change was greater in states with high-AIDS rate. Our analysis suggests that if individuals in low-AIDS states had experienced the same average AIDS rate as a high-AIDS state, the change in their approval rate from the '70s to the '90s would have been 50 percent greater.