Others would classify it as "conservative" or "libertarian" rather than "liberal". Which really means it's not a very effective "echo chamber". You will read opinions different than your own on HN. If that's upsetting to you, HN may not be your cup of tea.
I don't think anyone would classify the HN crowd as "conservative" in the US political spectrum sense. Libertarian I can see, but I don't think I've ever seen socially conservative posts/comments voted up.
