Jacoba Urist, The Atlantic: Guns, troubled young men, and violent video games. Together, they form a tragically familiar background story to America's recent shooting massacres in Columbine, Aurora, and Newtown. But the Constitution protects guns, and mental health is expensive and complicated to treat. So some lawmakers are responding to the latest tragedy by going after the third -- and possibly least consequential -- variable in this murky equation. There is a new push to tax violent video games.