Why are answers that question the politics of the US government classified against Yahoo terms?

You either did not answer the question actually posed or your answer was was a rant against the US, not an answer. No matter if question or answer, ranting, preaching, or giving a speech on a subject is a violation. Just answer the question.

If you want to know more about the reason for the violation, post "Why was this question (answer) a violation?" and add the original e-mail you get (within 24 hours) and any added details you remember so the users can see the exact context. The experienced users here will explain it to you. There is no statute of limitations on breaking the YA rules.

We would have to see what the answer was to help you. It might just be that enough people flagged it. I'm not sure what their policy is on deleting answers.

Imma guess it was the rant that's against the guidelines.