Background Ecological and cross-sectional studies have indicated that conservative political ideology is associated with better health. Longitudinal analyses of mortality are needed because subjective assessments of ideology may confound subjective assessments of health, particularly in cross-sectional analyses.

Methods Data were derived from the 2008 General Social Survey-National Death Index data set. Cox proportional analysis models were used to determine whether political party affiliation or political ideology was associated with time to death. Also, we attempted to identify whether self-reported happiness and self-rated health acted as mediators between political beliefs and time to death.

Results In this analysis of 32 830 participants and a total follow-up time of 498 845 person-years, we find that political party affiliation and political ideology are associated with mortality. However, with the exception of independents (adjusted HR (AHR)=0.93, 95% CI 0.90 to 0.97), political party differences are explained by the participants’ underlying sociodemographic characteristics. With respect to ideology, conservatives (AHR=1.06, 95% CI 1.01 to 1.12) and moderates (AHR=1.06, 95% CI 1.01 to 1.11) are at greater risk for mortality during follow-up than liberals.

Conclusions Political party affiliation and political ideology appear to be different predictors of mortality.