The meeting of the African National Congress party that began at the weekend is far more important in determining the future of South Africa than the nationwide poll to elect a successor to Thabo Mbeki in two years' time. For such is the dominance of the ANC that whoever becomes its leader will almost inevitably be sworn in as South Africa's third post-apartheid president in 2009. All the indications are that when the results of yesterday's vote are announced today, Jacob Zuma, the populist ANC deputy president and bitter rival of Mr Mbeki, will be confirmed as the winner. It is a result as depressing as it is ominous for the country's prosperity and stability.

Much of the blame must rest with Mr Mbeki, who sacked Mr Zuma as national Deputy President two years ago after he was linked to a corruption scandal. That action was courageous and correct. But despite a sensational rape trial last year, in which Mr Zuma was aquitted although tarnished by his squalid admission of sexual irresponsiblity, the front-runner took advantage of President Mbeki's failings to regain his political hold. He is everything that the shrewd but flawed President is not: earthy, approachable, an ethnic Zulu able to reconcile squabbling factions and a leftwinger who has pandered to the clamour for more redistributive policies.

Mr Mbeki, by contrast, has allowed himself to be seen as aloof, too cliquy, too much a tactician, who has allowed his sensible pro-business policies to widen the wealth gap and eclipse commitments to help the large number of poor and unemployed, especially in the grim townships. He has also alienated many South Africans by his bizarre denial of the Aids scourge, his refusal to take a tough stance against Robert Mugabe, while still allowing millions of Zimbabwean refugees to pour across the border, and his alleged use of state institutions to purge his opponents.

Mr Mbeki has been unwise in trying to stop his rival by smear tactics and leaks of tasteless reports on Mr Zuma's private life, including the suicide note of one of his four wives. If anything, this has had the opposite effect; Mr Zuma garnered the support of the ANC Women's League, despite the plea by Desmond Tutu, the former Archbishop of Cape Town, not to choose “someone of whom most of us would be ashamed”. Having already served two terms, Mr Mbeki cannot stand for the presidency again. But as ANC leader he would be in a position to block Mr Zuma. That may yet be possible, if enough party members are convinced over the next two years that the choice should have been wider. Shrewd and weightier politicians are still waiting in the wings, including the businessman and former trade unionist Cyril Ramaphosa. But whoever takes over in 2009 faces extraordinary challenges.

South Africa is by far the continent's richest, most developed and most influential country. But crime remains endemic, with one of the world's highest rape and murder rates. There are millions living on less than $1 a day. Corruption is officially acknowledged as a main threat to the economy. Land distribution (whites still own 90 per cent of arable land) has become more urgent, and more difficult, by Zimbabwe's catastrophic example. And infrastructure spending must rise fast to keep pace with economic growth. Convincing policies for all this must be outlined by the ANC's chosen president-elect. Mr Zuma, if it is to be him, has much to do.