Fusion GPS co-founder pleads the Fifth in Congress, attorney cries McCarthyism
Watch live: Obama delivers remarks at Mandela lecture
Former President Obama delivers the 2018 Nelson Mandela Annual Lecture in Johannesburg marking the 100th anniversary of Mandela's birth.
It is the former president's most high-profile speech since leaving office.
Obama is expected to speak at 8 a.m.
Watch live in the video above