Earlier quoted context omitted.
It is evidence that academia doesn't require evidence for left-wing claims. So to the extent that they do that, insisting on evidence from conservatives is discrimination. (I'd prefer that everyone's claims require evidence.) But https://www.johnlocke.org/academics-support-discrimination-a... speaks more directly to your question. Conservatives are discriminated against in academia for being conservative.
Doesn't this just mean that conservatives believe Marxism is an unacceptable worldview, since it exists? Why would we police evidence-based thought in academia?
But it is not. Evidence for Marxism that I've seen boils down to rhetoric. Evidence against Marxism involves mass famines, low economic productivity, failed predictions, and so on. Therefore a significant fraction of Marxists in academia must support it for reasons other than the evidence.