I'm not passing judgement on his stance, the ANC's actions, and even on whether terrorism is a good or bad thing. I'm merely stating that he did have prolonged support of the entity that we today call terrorism.
Terrorism is not an entity, so I don't understand what you are saying.
If you are saying that the ANCs actions make them objectively terrorists, I would say that I've never seen the term terrorist used in an objective and consistent manner.