I'll be honest and say that politically motivated killings are not something I know much about, at least in terms of getting below the surface. Certainly in the past it was much worse, even with the "rule of law" associated with an iron fist minority government and pliable Bantustan leaders. The proximal cause is essentially political infighting and maneuvering by internal ANC factions. Why it can happen in the face of laws and democracy? More difficult. On the one hand it's clear that the police don't actually have the power/resources to prevent this kind of thing happening. But on a deeper level, and in line with what I was saying above, the situation (or more accurately, the system) on the ground has not really changed much since the IFP/ANC/Third force "war" in the 80's and 90's. I guess what I'm saying is that the rule of legitimate law can hardly break down if it was never built up to begin with.