The obvious questions raised by the breakaway party led by Mbhazima Shilowa and Terror Lekota relate to its prospects for success, and its likely impact on the dominance of the African National Congress. But what are the likely effects going to be on the Democratic Alliance of Helen Zille?

Before the split in the ANC the DA was probably in a stronger position, electorally, than it has ever been before - indeed, stronger than any single opposition party has been since 1994. The survey conducted by MarkData between April and June this year (see here) found that the party enjoyed the support of 17,4% of respondents, 20,6% if non-respondents are included. This is a higher level of support than any opposition party has enjoyed - according to this series of polls - since 1994.

The DA is positioned to do well in the Western Cape in 2009 particularly as, seems likely, the breakaway party is likely to draw off substantial support from the ANC in that province. The MarkData poll found that among respondents in the province just over a third declared their support for the ANC and DA respectively. For the ANC this is considerably less than the 45% of the vote they received in 2004. For the DA, meanwhile, it is considerably more than the 27% they won in the last election.

In an analysis piece on the survey (see here) Lawrence Schlemmer noted that "One source of cautious optimism [for the Democratic Alliance] is that the process of slow accretion of black support has started. For example, the survey results show that admiration for the leader of the largest opposition party, the DA, has grown slowly but steadily. In 2004, 9% of African voters and 15% of all voters ‘admired' the major opposition leader [then Tony Leon], and by 2008 these percentages shifted up to 14% and 26% [for Helen Zille]. If 26% of the whole electorate admires the leader of the opposition today it indicates a base of sympathy that is larger than that of any opposition leader since Mr. FW de Klerk for a short period just after 1994."

In the short term then the breakaway party is going to throw up both opportunities and challenges for the DA. On the one hand, there is a danger that the new party will cannibalise opposition party support and/or draw away undecided voters sympathetic to the DA. ANC Secretary General, Gwede Mantashe, has predicted that since the new party was going to have a "centre right" orientation it would be "more likely to appeal to the constituency of many opposition parties." Moreover, if the breakaway fulfils its potential (see here) the DA could be challenged for the position of official opposition in parliament next year.

The threat the new party poses to the DA's support base is probably mitigated by the high levels of admiration DA supporters have for their leader. Zille is admired, or strongly admired, by 88,6% of DA supporters, with only 7,5% disliking her. By contrast Jacob Zuma is admired or strongly admired by 60,3% of the ANC supporters polled. (Incidentally, 75,8% of DA supporters dislike or strongly dislike Jacob Zuma, with only 10% saying they admire him in one way or another.)

On the other hand, if the breakaway does do well then this would open up opportunities for coalition government at provincial and later at local government level.

One of the open questions about the ANC split is to what degree it will facilitate a more pluralistic political system, and a more democratic ethos among current supporters of the ruling party.

In his report on the survey Schlemmer notes that "the DA's growth prospects at this stage are somewhat limited by considerable hostility to it among African voters. 65% dislike the DA leader and 14% admire her." This is due not to race but "what one could call liberation solidarity - a tendency among ANC activists and spokespeople to vilify and stereotype any leader outside the ANC Alliance." The potential for opposition growth is "made difficult by the political polarisation in the electorate that makes many if not most African voters hostile to any opposition, irrespective of its composition."

If the split shatters that ‘liberation solidarity' and softened attitudes to opposition this could create new opportunities for growth for the DA in the medium term. Unless it makes a spectacular breakthrough back into government the new party meanwhile is going to have trouble sustaining itself through to 2014. The DA has a set of core principles and convictions which has sustained it through fourteen years of ANC dominance (and forty years of NP dominance before that). It is not clear what will keep the breakaway going if power is seen to recede beyond its grasp.

One of the great strengths of the DA - in the current situation - is its record of opposition to the worst policies of the Mbeki-era. On HIV/AIDS, Zimbabwe, and centralisation, the DP/DA had a more outspoken and consistent record than either COSATU or the SACP (see here). This means that it is not vulnerable to the kind of critique now being directed against the leaders of the breakaway movement.

The DA is going to have to follow something of a Goldilocks approach when it comes to dealing with the breakaway. The challenge for Zille is to ensure that the temperature of her engagement is just right. If it is too warm the DA's record of opposition to Mbeki could become obscured, too cold and an important opportunity for inter-party co-operation and coalition government might be lost.

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