That's more recent, to be honest. When I started reading HN, it was very very libertarian (but mostly non-political).

As it's grown bigger, it's started to reflect the demographics of software/data/professional people, with a bias towards the West Coast of the US.

That's presumably what you mean by the liberal tech groupthink (note that disliking Trump does not make one a liberal, which is a mistake a lot of conservatives have made over the past four years).