I have no idea whether the parent poster is guilty of the things you accuse him of and it is actually hard to know what it actually takes to be accused of white supremacist sentiments [1] nowadays since that term has been bandied around by the usual suspects so much. The problem I see is that this site has started to look like /pol/ more or less since Trump 1 when the 'ban' on political posts was seemingly lifted as long as those posts were aimed against the orange man and his ilk. Either bring the ban hammer down on all posts political or keep it only for those few occasions where someone really goes over the line. The mentioned holocaust denial would be one as far as I'm concerned, same for the denial or glorification of other atrocities like the Holodomor/killing fields/Chinese cultural revolution/etc. Political dissent should never be a reason for flagging but unfortunately I've seen this too many times. The Athenians used to debate politics (among other things) on the 'agora' or 'meeting place'. They generally did not do this by kicking anyone who dissented off the square, they debated them. Sites like HN are the modern versions of that meeting place and kicking people off them because they happen to voice dissent does not do anyone any good.
[1] Here's a nice read-up on the subject: https://newdiscourses.com/tftw-white-supremacy/ ... and please don't tell me that James Lindsay is a white supremacist to avoid ending up in an endless loop. He isn't, not even when he says something you don't agree with, see https://www.itspronouncedmetrosexual.com/2019/07/maybe-we-sh...