Emma Stone, Melissa McCarthy, and Sheryl Crow are among a number of celebrities urging Americans to “reject the NRA” and concealed carry of firearms in the wake of the shooting at a Las Vegas country music concert this month. Laura Dern, Bill Hader, and Adam Scott are also taking part in the anti-gun campaign, as is noted gun control advocate Julianne Moore. The celebrities are part of the Michael Bloomberg-funded Everytown for Gun Safety PSA against the NRA specifically, and against gun rights generally. In typical Everytown fashion, the PSA does not present real solutions to the attack in Vegas–after...