While ABC’s World News Tonight and the CBS Evening News largely stuck Friday to the investigation into the Thousand Oaks, California bar shooting and the grieving families, NBC Nightly News went political. Their strategy? Well, NBC took it upon itself to push gun bans and gun control with support from both a doctor’s group that the National Rifle Association (NRA) had tweeted about (before the shooting) and comments from a grieving mother calling for “no more guns.” “Also, a war of words erupts, the NRA versus doctors fed up and speaking up after the latest mass shooting in America. And...