Basic Income stories are political, but they aren't purely political. There's an intellectual interest in thinking about and debating such a major social change. Political horse race stories are the opposite.

People tend to see HN as ideologically biased in favor of whatever they disagree with—that's a classic cognitive bias in its own right. Indeed there are some biases on specific issues (Snowden detractors don't do well here), but I'm not sure I agree they cut left or right overall. The community is pretty divided, much as the larger population is.