General Discussion

It's a basic human weakness. Demonization and dehumanization are pretty much prerequisites for mass violence, and to varying degrees have become characteristic of our public discourse (in politics and even entertainment and sports).

Efforts to acknowledge/address this tend to come off as superficial or naive, in part because the very dynamic you allude to predisposes us to cynicism. Reminds me debate questions challenging candidates to praise their foes in at least some small way (e.g. from 2016):

The MAGAt moniker, for instance, is dehumanizing and quite acceptable here on DU, for reasons I can sympathize with. I don't think the weight of hatred is remotely equal on "both sides;" proposals to detain, deport, or execute groups on the right are basically nonexistent, while the rhetoric on the right is much more explicitly violent. But self-awareness demands that we recognize the left shares in the same frailties as the right, whether or not we indulge our worst instincts to precisely the same level.