Marketing experts preach that redefining a market is the best way to win it over. This is why gun control politicos are now making an effort to change their messages, targets and tactics. Over the last twenty years or so, gun control has lost. They lost the constitutional argument. They lost the criminological debate. They lost the support of the general public. My hope was that they would continue doing exactly what they have been doing, because they would continue their losing streak and might eventually become a historical footnote. But they are getting shrewder, as evidenced by a new...