chicago barack obama make first major appearance since leave white house make mention monday successor donald trump urge young people get involve communities time stark political divide go since go joke former democratic president moderate event university chicago city begin political career site presidential library obama teach constitutional law school recall start young community organizer city tell panel six current former students decide focus post-presidency encourage young people engage communities single important thing help way prepare next generation leadership take baton take crack change world tell audience several hundred people obama largely stay public eye since leave office january despite efforts trump republican-led congress undo much legacy include healthcare environment trump republican say inherit mess accuse obama march without provide evidence wiretapping 2016 presidential campaign obama deny charge fbi director jam comey tell congressional hear see evidence support allegation obama ask trump students take question reporters say long goal bridge country deep political divide obama say hard hard find common grind money politics special interest dominate debate washington ways match broad majority americans feel say obama add change way people use media allow converse agree point view sunday part program help at-risk young people obama meet privately men chicago trouble south side discuss solutions violence joblessness mark neighborhood former president together wife michelle recently strike two-book 65 million memoir deal expect travel berlin meet german chancellor angela merkel next month obama make mention trump first major post-presidential appearance