(1) everyone with strong political feelings becomes certain that the site/community/mods/etc. are biased against them - see >>26148870 for plenty of examples, and here are a few recent ones in case it's helpful:
>>41799329 ("a haven for alt-right trolls and hateful abusers")
>>41674836 ("the libertarian tech bro site")
>>41370117 ("The HN crowd is far right")
(of course there are also many examples expressing the opposite perception, because the dynamic is the same either way: overgeneralization from the sample of data points one happens to notice/remember, which are more likely to be cases one dislikes [1])
...and...
(2) the error where people are convinced that HN has become much more political lately—I suppose because of recency bias or something. This perception has been around for almost as long as HN itself [2] and the way we handle politics on HN has been the same for many years [3]. Of course it goes through fluctuations but those are fluctuations in the topics themselves, not HN.
[1] https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
[2] I put this collection together quite a few years ago already: >>17014869 - and you can see how little it has changed via https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que....
[3] https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...