I don't think it's so much about politics, as it is about a combination of affluence and ignorance. Some of the biggest proponents of the anti-vax stuff are rich, affluent, and uneducated wives of men who stay out of the debate (i.e. Jenny McCarthy). They are basically soccer moms who have created their own anti-intellectual ideology derived from psuedo-science and a sense of entitlement about their children and society at large. These parents don't even understand why vaccines exist, to them disease is something you see on television or when you visit your dying relatives to peg down your spot in the inheritance.
You have to think of it from the perspective of a 30-something mother with a highschool education, who spends all her time watching reality TV and taking care of her kids. I am not saying that a person is bad because they do these things at all, and these women aren't bad people, but they have zero business setting public policy in the US regarding anything let alone our Medical system. A good majority of the anti-vax crowd probably would have trouble writing a 5 page book report on Lord of The Flies. They just don't understand what a disease is, how it works, or why they should care about anything scientific. They have gone through 30 something years without learning any of this and the biggest thing is when they think back and say "Well, I was vaccinated, and I never even needed to be! Nobody gets these diseases. My child will be fine, it's all conspiracy".
Much of all of this is the fault of the massive "Autism" circle jerk going on over the last 20 years in the medical profession. In the 80s and 90s it was "ADD and ADHD", and they stuffed our kids full of amphetamines. Now it's autism and their solution is to let their kids get horrible preventable diseases in the hopes of avoiding a disease that for the most part appears to be inherited. It's nothing more than stupidity. Where you have incredibly affluent, stupid people... you will have anti-vaxxers.