HN's bubble is a bit more tone-sensitive, where rowdy rabble-rousing from any side usually gets squashed...but the thresholds of tolerance are a bit skewed with softly-worded comments.

Carefully crafted traditional/conservative comments do get voted up, particularly if written knowing that they're addressing a potentially hostile audience. Those posting progressive viewpoints can generally get away with more blunt/aggressive language.

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.