Ta-Nehisi Coates returned to home to The Mecca, where he spent the day interacting with Howard University students — some of whom he praised for stumping him with insightful questions. The MacArthur “Genius” Grant recipient participated in master classes and an evening event that filled Cramton Auditorium, where he discussed everything from history and identity to his award-winning articles for The Atlantic and new book, “Between the World and Me.”