Source: khaled Ahmed / Getty Natchez, Mississippi. April 20. A 4-month-old baby, soft and new, still learning the shape of air, lies on the ground beneath a car. His mother’s foot rests on his stomach as if his body were something to hold in place. He is small against the pavement. His limbs are splayed, and his face is tight with confusion and distress as he cries into a world that has already turned hard beneath him. His 27-year-old mother, Ap…