Wading through a disturbing morass of arguments about whether George Zimmerman is white or Hispanic, whether Trayvon Martin attacked Zimmerman before Zimmerman killed the unarmed 17-year-old, and, stupidest of all, how much anxiety should be produced by the sight of a hoodie, I’m a bit dumbstruck that few seem to want to argue about the obvious: The direct cause of this tragedy was a frightened (and unbalanced) man with access to a handgun.