If roads were collapsing all across the United States, killing dozens of drivers, we would surely see that as a moment to talk about what we could do to keep roads from collapsing. If terrorists were detonating bombs in port after port, you can be sure Congress would be working to upgrade the nation’s security measures. If a plague was ripping through communities, public-health officials would be working feverishly to contain it. Only with gun violence do we respond to repeated tragedies by saying that mourning is acceptable but discussing how to prevent more tragedies is not. “Too soon,” howl supporters of loose gun laws. But as others have observed, talking about how to stop mass shootings in the aftermath of a string of mass shootings isn’t “too soon.” It’s much too late.