Entering stage left after the departure, to rapturous applause, of a living saint was never going to be easy. But other harsh realities make it an even tougher call. Five years after South Africa's first democratic elections - a period in which racial reconciliation was the main political thrust - a rougher political phase is about to begin, during which the fundamental social and economic changes necessary to deliver long-promised improvements to the black majority will take place. The gloves, the ANC keep warning, are coming off.
While President Mandela's bid to build a Rainbow Nation was helped by the breathless, intoxicating optimism that flavoured the fledgeling democracy's early years, Mr Mbeki enters this new precarious phase dogged by widespread public cynicism - with blacks annoyed at the slow pace of change and whites anxious about any erosion of their privileges - and a resurfacing of deep racial divisions.
When the ANC sweeps the polls for a second time, as it will in just 11 days, Mr Mbeki, currently the Deputy President, will assume power fully aware that while Mr Mandela could bask in love from across the racial spectrum, he himself already polarises public opinion. For Mr Mbeki is chief bogeyman at Johannesburg's liberal white dinner parties, and a worrying political force for a significant section of his own party.
Of cute garden gnome proportions, Mr Mbeki appears entirely inoffensive, though positively dull compared to the charismatic Mandela. Puffing on his pipe at party conference, he looks more like a benign university professor than a politician. But his critics insist that behind the clouds of tobacco smoke lurks a Machiavellian control freak who, since the unbanning of the ANC in the early Nineties, has busied himself ruthlessly eliminating all rivals for power.
In jittery, post-apartheid South Africa, where conspiracy is still king, and rumours are legion and often wild, it is wise to start with what is currently known about Mbeki. The "facts" are quickly assembled, for although Mr Mbeki has been running South Africa from the wings for the past two years, much about him remains a mystery. "We are about to be governed by a man we do not know," is how one South African newspaper described the transfer of power. Mystery, of course, leaves no end of room for rumour and white paranoia.
Thabo Mbeki was born in 1942 in the Transkei into a family already steeped in the struggle against apartheid, and into the Xhosas, the tribal group of Nelson Mandela and many of the ANC's leading figures. By his late teens, Mr Mbeki was the ANC's youth organiser. He fled into exile in 1962, at around the time when his father, Govan Mbeki, now 88, was jailed for treason by the apartheid regime, along with Nelson Mandela. It was the start of nearly three decades of imprisonment on Robben Island for almost the entire high command of the ANC, whose capture left the liberation movement in tatters.
While Mbeki senior languished in jail, his son studied economics at Sussex University. After his degree, Mr Mbeki - like his father, a member of the Communist Party - went to the Soviet Union for a spot of military training. But it was on the international diplomatic stage, not in bush combat, that the urbane, scholarly Mr Mbeki was to make his mark and win the admiration of his father's generation, who were growing old in isolation just a few miles from the golden beaches of Cape Town.
As political adviser in the Seventies and Eighties to Oliver Tambo, head of the ANC, who was in exile in Lusaka, Mr Mbeki lobbied against apartheid across the globe, building up a formidable network of connections in foreign governments. He is credited with masterminding the sanctions campaign that led to South Africa's international isolation, which in turn helped to cripple its economy.
When the battle for power within the ANC began after Mandela's release in the early Nineties, between the exiles and those who opposed apartheid at home, Mr Mbeki's sophisticated worldliness strengthened his hand against his main rival, the more charismatic and popular Cyril Ramaphosa.
This much is known, but it hardly adds colour to the seemingly cold fish who is replacing Mandela - the smiley, jiving pensioner in love who, despite his royal upbringing, has the common touch Mr Mbeki singularly lacks. The slipping of a few warm personal details might help. But for whatever reasons - shyness, paranoia or a belief in a politician's right to privacy - Mr Mbeki gives few, if any, titbits away.
The "facts" about his personal life - such as his marriage to Zanele, who is seldom seen with him on the political trail - could be written on the back of a cigarette packet, though during the Truth and Reconciliation Commission hearings it was revealed that one of his brothers had been missing for years, presumed murdered by the security police. There were also rumours that he had a son - another that he had two - who was also murdered trying to escape from South Africa in the early Eighties.
Then last month the writers of a new Mbeki biography claimed that there had been a son, Kwanda, a "love child" Mr Mbeki fathered in 1959 when he was just 16. According to The Life and Times of Thabo Mbeki, by the South African journalists Adrian Hadland and Jovial Rantao, Kwanda's mother was the daughter of a school principal, and her pregnancy scandalised the local community. Mr Mbeki's family, the book claims, had to pay a fine of five head of cattle to her family for this transgression.
For a man who values his privacy, the "revelation" on the eve of the presidency has been, to put it mildly, unwelcome. Mr Mbeki's office has condemned the "sensationalism" and a spokesman insisted it was no secret that Kwanda was Mbeki's son.
In neighbouring Zimbabwe, President Robert Mugabe has jailed journalists for daring to write about his love life. And while it is inconceivable - yet - that that could happen in South Africa, the "love child" stories only feed the president designate's open hatred of the "white-dominated" media that he has threatened, on numerous occasions, to crack down on. He has suggested that the media's role should be solely to inform the people about what the government is doing for them.
It is not so much the media, as criticism, that Mr Mbeki cannot seem to tolerate. Even President Mandela - whose support, at least in private, is not always unequivocal - appeared to issue a thinly veiled warning at a party conference against Mr Mbeki's tendency to surround himself with yes men.
The whites who now hang off the edge of Cape Town on the last stage of their hysterical flight from black-governed Africa might be expected to bad-mouth the man who will replace President Mandela, who always did so much to mollify and reassure them. They even blame Mr Mbeki for the caustic criticisms Mr Mandela levelled at them during his last year. Mr Mandela's lips were moving, they say, but it was Thabo Mbeki's voice that spoke.
However, criticism also has a black face. The party's rank and file - and particularly the "home" activists - whisper nervously about the way Mr Mbeki has attacked popular party figures. He is accused - though never publicly - of orchestrating whispering campaigns against his rivals, engineering their demotion or departure from the political fray. But Mr Mbeki, of course, also has fans within the ANC, who ask for proof to back any of the Dark Prince accusations. And they point out one undeniable truth. President Mandela was many things - unifying force, symbol of hope and forgiveness, clever communicator, man of vision - but he was never a politician. On the international stage, he was, quite frankly, sometimes a disaster.
Mr Mbeki, a seasoned diplomat and undeniably an intellectual, is the man, they say, for this particular hour - and a man who also offers vision. It was Mr Mbeki who brought the world African Renaissance, and the bold notion, eagerly snatched up by the US President Bill Clinton, that the world's most shambolic continent could pull itself up by its own bootstraps. (Though, sadly, a string of subsequent conflicts have ensured that the Renaissance has remained languishing at the level of mission statement.)
And there were signs this week on the campaign trail that the man more at ease in the corridors of power than campaigning at the grass roots was at least trying to hang loose and touch the people. In his native Transkei, still far from comfortable, he was at least pressing flesh, if not quite kissing babies. In his family village, where he visited his mother, villagers slaughtered a goat in celebration while he apologised to the rural poor - threatening to desert the ANC for the opposition United Democratic Movement - for the urban bias of his party.
The usual sharp suits were left at home and open-necked sports shirts, that no one imagined he even possessed, were donned. But these are clearly early days. He displayed a William Hague-like knack for just missing the sartorial target. The jacket was just too well-cut to be casual.
It could be some time before Mr Mbeki hears a stadium ring to an anthem singing his praises - he currently has just one song dedicated to him, compared to the huge range in honour of Mr Mandela - but he clearly won some new support. Would they miss Mandela, the people were asked? "Of course," said one resident. "But Mandela is an old man now. And it's time for Mbeki."
None of this matters a fig, of course, to international business, outside investors or global markets. Only the economic path Mr Mbeki's South Africa will follow is of concern. South Africa has pleased the West by following IMF-style orthodoxy, adopting tight fiscal controls and embracing capitalism rather than socialist economic solutions. It has done so despite tremendous pressure from the trade unions and the Communist Party, the ANC's traditional allies. Though Govan Mbeki says Communism was so ingrained in his son that he cannot have forgotten it, there is no reason to think that the country's economic strategy will change. After all, Mr Mbeki has been in charge for quite some time.
He will, however, have to walk an increasingly precarious line between delivering political promises to an already impatient black majority, and keeping international business onside. At a time when South Africa and other emerging markets are under siege, Machiavellian or not, that balancing act will demand all of Thabo Mbeki's political skills.
A Concise History
ANC stalwart Origins: Born at Idutywa, Transkei, 18 June 1942. Education: University of Sussex. MA in economics, 1962-66. Family: Son of the t Govan Mbeki. One of four children; one brother missing, presumed murdered by apartheid security forces. Married to Zanele since 1974. Struggle credentials: Leader of African Students Organisation, 1961; youth organiser of the ANC, Johannesburg, 1961-62; exile, 1962; ANC official, London, 1967-70; military training, USSR, 1970; ANC official, Swaziland and Nigeria, late 1970s; political adviser to Oliver Tambo, Lusaka, Zambia, 1970s and 1980s; deputy president of South Africa, 1994. Pastimes: Voracious reader of the classics. He says: "You cannot have real national reconciliation of a lasting kind if you don't have a fundamental transformation of society." Mandela says: "He is a young man with a very favourable political background." FW de Klerk says: "I have developed respect for him, for his intellect and his managerial capacity and I think he is truly committed to a fairly balanced economic policy."