Christmas decorations light the streets. Malls are full. Christmas music fills the air. But this year, there is a somber undercurrent to the celebration. We will all hug our children a little harder. Our hearts will be in our throats as they go out to play. After the horror of Newtown, we remember how precious and how vulnerable they are in a country that is drowning in guns. Some good news can be told, however. Violent crime, teenage pregnancy, binge drinking and cigarette smoking are down. Yet, one in five children in the U.S. is now living in poverty — …