If you allow some 'important' off-topic posts, you need to either have an externally-imposed decision on what's important (ie, a moderator who uses their idea of 'important'), or accept that you're going to see a stream of 'important' posts that you don't care about.

As a community maintainer and moderator in the past, it's an issue I've struggled to get people to understand, as they all assumed that their pet issue was important enough that it didn't matter it was off-topic.

It's not points-of-view that I'm describing as important, it's certain news stories.

Does anyone doubt that the Egyptian revolution is a very important story in world affairs?

Politics is a perfect storm of signaling where real-world consequences are almost completely divorced from argumentation. It's the opposite of hacking and startups, where assumptions and opinions are tested in the real world constantly, and feedback is quick and unambiguous.