The cynical view, which has accompanied Mazibuko's rise within the party, has it that she represents exactly what the DA needs to survive and give the ANC real competition.

Mazibuko is the epitome of post-apartheid young-black, South Africa - confident, articulate and ambitious. Nothing wrong with that. It is exactly what party boss Helen Zille would have defined as the future of the DA. It is the only way for the DA to grow beyond the gains it made after 1994.

This year's local government elections illustrated both the ambition and the frustration of the DA. It has grown a black constituency but not by any means by enough to dent the ANC's majority.

But will a victory of Mazibuko over Trollip, and continued reaching out for elusive black support, signify the end of the original DA, a severing of the party from its roots?

For Trollip represents the "old" DA - with its roots in the Progressive Federal Party and the Democratic Party - far more than anyone else currently in the party leadership.

He is, in effect, a dinosaur from the days of Tony Leon, representing old, white English-speaking South Africa.

Pushing Trollip to the margins might just signal to many in the DA's historical support base that they no longer matter.

Zille's open support for Mazibuko is more than just a ploy to gain black votes - it is a real shift for the DA. She should be careful though that she does not leave parts of her rainbow coalition of supporters behind.

Mazibuko, who has endured many racial jibes, including by ANCYL president Julius Malema, has shown that she does not wilt under pressure. And that she and others like her might well be the salvation of the DA.