"My Facebook followers have incredible compassion for war victims in South Sudan, for kids who have been trafficked, even for abused chickens, but no obvious empathy for conservative scholars facing discrimination."
miss the mark. Excluding people based on their beliefs is completely a judgement call about whether you think their beliefs are so far from your own that nothing productive can come from sharing a department with them. The feelings of the author (and me, and a lot of others besides) is that staunch liberals in academia might be flawed in excluding conservatives. But not because it's akin to racism, it's a different (and less objectionable) type of discrimination.