The sad part is that Daddy Berg's left-leaning idiology contributed much, much more to his son's death than any right-leaning idiology. Daddy Berg doesn't want to admit or see that. Daddy Berg is blinded by his own idiology. Now, Daddy Berg needs to blame someone. He chooses the right-leaning/Republican Bush administration, so he can keep his idiology in tact. His choice was wrong because no Presidential administration forced, coerced, or made his son go to Iraq. That was Nick Berg's free choice.
Having worked for years with cancer patients and their families, I have to say that anger is sometimes a reaction to a loved one's death. It's more empowering than simple grief and sadness, and it often takes an inappropriate direction. Given the horrific nature of Berg's death, I'm not surprised at the anger of his father. It's just too bad that he won't really face up to the truth, which seems to have been a trait that ran in that family.
Maybe Nick went there to get away from "Daddy".