The story is mainstream politics, which is off topic. It presents no new or interesting phenomenon of intellectual interest, nor does it bear an even tangential relationship to technology. And, as expected, the threads posted have mostly devolved into partisan shit-flinging or complaints about the mods.
This isn't censorship or improper flagging, it's an attempt to keep Hacker News from descending even further into the cesspool of politics. The bar for these kinds of stories needs to be set much higher than it has been.
Kind of smells like censorship, or at least mod indifference to a group of users improperly flagging these:
https://news.ycombinator.com/item?id=16579219
https://news.ycombinator.com/item?id=16578715
https://news.ycombinator.com/item?id=16576569