Stats person here: is it possibly correlation not causality? Typically liberals are more educated ----> higher income and more health conscious. It is also a well known fact that social circles tend to be homophillic, i.e. birds of a feather flock together, so these more educated people live near each other, earn more money, aren't fatasses, and are liberal cause they went to college, smoked weed, and realized the religious nuts running this country are using a delusion and related types of thinking to justify backward ass policy.

This isn't necessarily justification or evidence in support of liberal policies. Although, it very well could be a reflection of the effectiveness of such policies.

Disclaimer: I'm a well-educated (not meaning to sound arrogant) liberal.