I haven't argued in favour of communism, but I
have expressed opinions on HN that went against the herd, and I have fared well. (See:
http://news.ycombinator.com/item?id=1661588)
I've said this before, and I'll say it again: HN is largely self-correcting. The trick is to write a response when you get downvoted (unfairly, that is), because the downvote is usually a signal that either: a) you wrote a lousy one-liner or b) you didn't express your opinion in a clear manner - see (a).
Flesh out your argument, tell people that you do have a point, and say that you don't think the downvotes were fair. You'd likely see a correction within the next couple of hours.
This of course assumes that you do have something intelligent to say. If you don't, the downvotes are deserved.
Also, I note that in your response to the parent's comment you've not articulated your arguments. You merely make assertions.
not in all cases.
What does that mean? Why do you think so? What counter-examples can you give us?
that goes with the herd
What does? Why? And you link to a HN thread, expecting us to see ... what? What is it that you see in it that you want us to notice, as well?
HN karma rewards the most cogent, the most intelligent comments. Those are usually well articulated ones. Simple assertions are not well articulated arguments, even if they are true.
A simple format for writing a clear argument is to use the framework of: Assertion -> Reasoning -> Example. HN may occasionally downvote comments based on content. But only if the argument isn't well articulated. That's been my experience, at least.
PS: if you're a karma lover, you may be in this for the wrong reasons.