What the DA doesn't seem to understand, is in the current political climate in South Africa, if they want votes, they CANNOT have Zille as the party leader, purely for the fact that she is white.
This is unfortunate, but if they want votes from the majority, or even if they want more votes, they need a black person, preferably a male black person in charge, or at least as so-called 'face' of the party.
They will never get where they want to be in the current state of South Africa with Zille as the head.