The event will be a homecoming for Obama on multiple levels. He formerly taught constitutional law at U. of C., and his family has a home nearby in the Kenwood neighborhood. He gave his farewell address in January in the city that launched his political career. And the discussion with students lets the former president, who came to Chicago to work as a young community organizer, fulfill one of the commitments he set out for his post-presidential years: to engage and work with the country's next generation of leaders, Lewis said.