Citing the recent controversy over his comments on same-sex marriage, neurosurgeon and rising conservative star Dr. Benjamin Carson has voluntarily stepped down as commencement speaker at the Johns Hopkins School of Medicine. The Baltimore Sun reported that Carson, who heads the department of Pediatric Neurosurgery at Johns Hopkins Hospital, informed medical school Dean Paul B. Rothman in a letter that he didn't want to "distract from the celebratory nature of the day." "Given all the national media surrounding my statements as to my belief in traditional marriage, I believe it would be in the best interest of the students for...