Why was this flagged/dead? I'm not sure how the voting system works here, and saying "it's political/not relevant to HN" is not a good reason, considering the anti immigration article on the front page from theamericanconservative.com
It currently does not have a '[flagged]' tag from what I see, though user voting may have changed in the time between the posting of your comment and mine. What gives you the impression that it's flagged?
I had to "vouch" it, something I haven't done before. Previously it was dead/flagged.
As to why some posts are flagged, and some to the point of '[flagged][dead]', from as much as I've witnessed it's not all that dissimilar to why some posts or comments get up-voted and others not. Certain occurrences of flagging will catch our eye based on our own perspectives.
I haven't been convinced strongly enough that there's anything nefarious afoot to warrant diving into looking at the post statistics (though I do think it would be interesting to do so). From your initial comment I might assume that you think this might be the case. If so, I encourage you to do such a study yourself. The HN APIs will likely give you enough data to provide enough data to dig into it.