Mike Bloomberg put $50 million into Tuesday's elections, and he doesn't have much to show for it. Someone, perhaps the Koch brothers, ought to treat him to a Big Gulp. The onetime mayor of New York City organized a group called Everytown for Gun Safety, meant to rival the National Rifle Association, and with a lot more money. The new group was supposed to put gun control on the front burner. Instead, the gun-control candidates got scorched on the back burner.