CHICAGO - Less than 3 miles from where former President Barack Obama and first lady Michelle Obama broke ground last week on their long-awaited presidential center on the South Side of Chicago, Tahiti Hamer lies awake at night thinking about the limited time she and her family have left in the neighborhood where she's lived her whole life. Following the announcement of the center in 2015, neighborhoods adjacent to the 19-acre planned site have seen skyrocketing rents and housing prices, and Hamer, 42, a single mother of three, is one of several facing displacement. Hamer, a teacher at a local...