You didn’t hear the word “guns” voluntarily pass the lips of any Democratic speaker at this week’s convention in Charlotte, N.C. Liberals may be smart enough to avoid alienating the almost half of all Americans who have guns in their homes, but the same can’t be said for their party platform. The Democratic policy statement approved this week calls for enacting “common-sense improvements — like reinstating the assault-weapons ban and closing the gun-show loophole.” The so-called “assault-weapons ban” in the 1990s banned scary-looking guns and magazines that held over 10 rounds. The platform does toss in a line that claims...