The way this sounds is that you are more concerned about politics as in people who take party positions and may feel excluded as a group when the majority of the community takes a different position. This is a slightly different issue i.e. party politics, and I think it is fine/a good thing, but it is also important to distinguish the two. This should essentially be under the same umbrella as personal attacks, as they are essentially the same thing.
I'd rather see HN go politics-free forever. Political discussions do not enjoy the same level of objectivity that technical and business discussions do. Frankly, it may be impossible to expect objectivity within political discussion because our political feelings are so deeply-held and tied to our individual upbringings, culture, and locale.
Unless HN can figure out how to give fair treatment to minority opinions, it's best to exclude these discussions entirely.
For example, you could use your justification for banning any discussion about HN's rules since that would also be subjective and have minority viewpoints unfairly downvoted. People are often passionate about any rules changes as we can see by the upvotes on this submission. Do you think discussion about this rules change should be banned too?