There is an interesting phenomenon happening here on hacker news.

Optimistic comments are being voted down by the moderators (who have a high enough ranking to do so). Yet, this article has been pushed to the top by regular members.

The messages within the down-voted comments aren't breaking any of the community rules. So the down-voting is happening because of a political disagreement. The moderators are intolerant of an opposing view and rather than engage in open debate; they instead wink the things they disagree with, out of the conversation entirely.