There is something unspeakably shocking about any mass shooting. There is, sadly, something less shocking about a transgender mass shooter. Yesterday, 23-year-old Robin (formerly Robert) Westman, ambushed the back-to-school Mass at Annunciation preK-8 School in Minneapolis. He was armed with an assault rifle, a shotgun, and a pistol, and he brought two-by-fours to barricade the door to…