On Saturday, family and friends gathered to mourn the loss of Hadiya Pendleton, shot to death last month at age 15 in a South Side park. Michelle Obama graced the memorial with her caring presence, a mother comforting a brokenhearted family for the unbearable horror that took place about a mile from the Obama home in Kenwood. The first lady’s presence brought dignity, stature and the reassurance of concern and compassion from the highest level of government. Now, the White House will give national attention to the violence that is scarring Chicago. Hadiya’s parents, Cleopatra Cowley-Pendleton and Nathaniel A. Pendleton, …