My perspective is slightly different. I don't see it as a actual obsession. Quite honestly I don't think they give a rip about 'perceived racism'. I see it as 'all they've got'. The left is completely bereft of any substance whatsoever. They have nothing else to argue or offer anyone. In the absence of any intellectual honesty or substance the merely throw racism epithets. The intend to back off all opposition they are not prepared to defend against.