It was a cold morning in Phoenix, two days before Christmas. Temperatures had dipped into the low 30s, making the car, even with the few blankets they had, uncomfortably cold. Marvin Jackson and his wife, Melba were huddled together in the front seat. Melba’s feet, covered by heavy woolen socks, rested on top of the small cooler on the car’s floor. Their three children, girls 6, 9 and 14, were taking turns sitting in the middle seat, trying to keep warm...