At the start of this decade President Thabo Mbeki was in an immensely powerful position. The African National Congress had two-thirds of the seats in parliament and control over all the levers of power (with the exception of the judiciary). His personal loyalists filled key positions across party and state. The ANC had adopted rules of ‘democratic centralism' which essentially precluded an organised challenge to the party centre. He was fêted in Western capitals as the saviour of Africa, most of our civil society was completely pliant, and the ANC itself was bewitched by his intellect.

Yet within the next two weeks - barring the unforeseen, or some monstrous subversion of the democratic will - ANC delegates to the national conference are probably going to vote him out of office. How then can this extraordinary turn be explained?

Part of the answer lies in the paradox that Mbeki accumulated too much power and too little. As the ancient philosophers recognised, unfettered power is not necessarily an enduring kind. In The Politics Aristotle wrote that "royalty is preserved by the limitation of its powers. The more restricted the functions of kings, the longer their power will last unimpaired; for then they are more moderate and not so despotic in their ways; and they are less envied by their subjects."

Mbeki's centralisation of control over party and state patronage, between 1997 and 1999, allowed him to rapidly consolidate his authority over the ANC. Yet it also brought with it a sense of impunity and a lack of moderation. Mbeki's quixotic challenge to the scientific orthodoxy on HIV/AIDS - particularly after its reversal in April 2002 - fractured his intellectual authority over an ANC which had previously been in awe of his brilliance. The steady drip of revelations about the corruption behind the otherwise inexplicable 1998 arms deal has steadily eroded his moral authority.

The thuggish and intolerant demeanour of Mbeki's enforcers has also done his cause no good. Initially, this tendency to malign and insult Mbeki's detractors proved useful in silencing criticism and isolating opponents. But over the years it has converted much mild and uncertain dissent into hardened enmity.

(As an aside, the Mbeki-ite push for gender "parity" at all levels of the movement may stem from a deep-rooted commitment to equality between men and women. Or, it may just be because - as Aristotle wrote - "slaves and women do not conspire against tyrants.")

The downside to Mbeki's control over the levers of power has also become steadily more apparent. Patrick Laurence observed back in 2001, "Mbeki may yet pay the price of ‘democratic centralism'. Under that system of governance accusing fingers point in one direction only if promises are unfulfilled, hopes dashed and disillusionment magnified."

This is a prediction that has now come to pass, not least within the ANC itself. An unnamed "senior ANC MP" told the Sunday Times last weekend that "The outcome we are seeing is a result of the way in which [Mbeki] has been behaving for many years, but particularly since 1999."

Through his actions, the ANC MP stated, Mbeki had created a "coalition of the wounded" which had now rallied around his aggrieved deputy. Jacob Zuma had "become a symbol for all of those who feel they have been victims of an Mbeki presidency, be they from the left, the middle class who have failed to get tenders, the poor who have no jobs."

It is noticeable that it is the injuries which Mbeki is perceived to have inflicted which are remembered, not the many material benefits he secured for the party faithful. This is simply a reflection on human nature. As Tacitus wrote, "Men are more ready to repay an injury than a benefit, because gratitude is a burden and revenge a pleasure."

The ANC's extension of control over the prosecution service in 1998 was probably unavoidable, given that the arms deal was being put in place at around the same time. But, again, such centralisation has ended up undermining Mbeki's interests. As Niccolò Machiavelli warned in The Discourses, it is highly advisable for a ruler not to "have under his immediate control the judges and magistrates that decide civil and criminal causes, as no sentence pronounced by them will bring censure and odium upon him, and thus he escapes many occasions for calumny and hatred." The perception of those within the ANC subjected to investigation and prosecution (self-serving though this may sometimes be) is that the hidden hand of Mbeki is behind their misfortune.

Thus, to conclude, Mbeki had too much power in that it tempted him into a loss of self-restraint. It also generated much resentment and envy inside the party. However, none of this would have mattered so much if - having gone down this road - Mbeki had secured "power enough to rule over his subjects whether they liked him or not."