Politics....nature or nuture?

So Melanie made the observation about how all three children from a politically moderate mother currently range across the entire political spectrum. That made me think....what exactly causes that? Hard-wired into our brain? Environment? Both?

Here is a partial family listing (tree structure is not cooperating) with political affifiations (as best as I know). If you can provide corrected information, email me and I'll make a more complete picture.

Larry & Wendy
Republican Republican?

CJ, Linda, & Edie
Cult Leader, Moderate Republican & Republican?

Melanie & Paul
Libertarian & "Centrist"

Stephanie & Steve
Democrat & Democrat

Chris & Michelle
Republican & Republican

Adam & Katie
Democrat? & unknown

So, the nature option obviously does not hold much weight. But, the nuture one has issues as well since our upbringing was generally non-political, so how did that spectrum arrive? I lean to a combination....ex: I've always been fairly hard-core Republican, but I'm also very Pro-Choice (I saw first hand the effects of many unwanted teenage pregnancies in south Mississippi).

Thoughts?