On a chilly afternoon at a community clinic in Southeast Washington, three young doctors are busily laying the foundation for the health-care law's success. Jacob Edwards flips through a manual on skin conditions, diagnosing a rash that looks like chicken pox. Jessica O'Babatunde consults her supervisor on treating an adolescent's obesity, which is literally off-the-charts. And Julie Krueger peppers 3-year-old Daphauni with questions at her physical: How do you spell your name? What did you eat for breakfast? What's your favorite vegetable? (Cheese.) They are primary-care residents at Children's National Medical Center. A third of their class has more than $200,000 each in student loan debt.