The photos from doctors came quickly and in succession: blood-stained operating rooms, blood-covered scrubs and shoes, bullets piercing body parts and organs. The pictures on Twitter were an emotional response to a smackdown by the powerful gun industry lobby, which took issue with the American College of Physicians’ call late last month for tighter gun control laws. The recommendations included bans on “assault weapons,” large capacity magazines and 3D-printed firearms. “Someone should tell self-important anti-gun doctors to stay in their lane. Half of the articles in Annals of Internal Medicine are pushing for gun control. Most upsetting, however, the medical...