From S. V. Subramanian and Jessica Perkins.
They write:
The observation that Republicans enjoy better health status may reflect the core Republican value of individual responsibility, which could translate into increased adherence to health-promoting behaviors. It is also likely that Republicans tend to exhibit greater religiosity compared to Democrats.5 This could lead to health promoting social conditions, such as enhanced social ties and networks, in part facilitated through increased attendance in places of worship.
Our observations should not be interpreted to suggest that a Republican government necessarily equals better health. It would be erroneous to draw macro inferences based on individual-level correlations. Indeed, the question of which type of political ideology, reflected at the government-level, is better for population health or for reducing health disparities are entirely different queries. At the same time, our findings suggest that certain aspects of Republican ideology may implicitly be health enhancing for the individual. The healthier status of Republicans might also explain, perhaps, why they place lower priority on health care.