American conservatives tend to rate their mental health more positively than their liberal counterparts. One explanation for this finding is that conservatives may be more likely to justify existing inequalities in society, leading to a palliative effect on their mental health that does not happen for liberals. Conservatives also score higher on personality and attitude measures, such as religiosity, marital status, and patriotism, which are associated with better mental health. We examine whether this ideological mental health gap holds for a different facet of well-being that is closely related to mental health. Further, we suggest that the ideological mental health gap may have more to do with a stigmatized reaction to the term “mental health” which has become increasingly politicized in the US context since its introduction to literature in the early 20th century. First, we examine whether the conservative-liberal divide in self-assessments of mental health remains once we control for a wide variety of demographics, socioeconomic factors, and recent life experiences. We find that accounting for these alternative explanations reduces the gap by about 40%, but that ideology remains a strong predictor of mental health self-reports. Second, we conducted an experiment where we randomly assigned whether people were asked to evaluate their mental health or their overall mood. While conservatives report much higher mental health ratings, asking instead about overall mood eliminated the gap between liberals and conservatives. One explanation is that rather than a genuine mental health divide, conservatives may inflate their mental health ratings when asked, due to stigma surrounding the term. Another possibility is that ideological differences persist for some aspects of mental well-being, but not others.