From the FAQ: https://news.ycombinator.com/newsfaq.html
> The basic algorithm divides points by a power of the time since a story was submitted. Comments in threads are ranked the same way.
> Other factors affecting rank include user flags, anti-abuse software, software which demotes overheated discussions, account or site weighting, and moderator action.
This could very well be marked as an overheated discussion.
This comes up on HN constantly. The reason I feel confident that this is actually the case and not selective moderating is that these same exact comments pop up across posts from the entire political spectrum.