First of all, you completely missed the main point of my comment. If you think there’s no evidence then you shouldn’t be claiming one way or the other either, yet this post is presenting him as definitively right wing.

Secondly, I didn’t say he is a left winger. I said (based on my judgement) the evidence shows he probably, maybe leans left.

And answering your “what evidence” question, his text message to his roommate is released by the investigation. There are also statement from his mother stating he is “getting more and more left” (obviously, grains of salt). And there are leaked (released?) Discord messages from the killer.

If you never heard any of these, then you probably are in an echo chamber.