Mugabe's main challenge is a crisis of legitimacy in the Zanu PF system

The critical weakness that will eventually topple Mugabe is a failure of legitimacy. In political science, legitimacy is the popular acceptance of an authority, usually a governing law or regime. A political regime is legitimate when its participants have certain beliefs or faith in regard to it: "the basis of every system of authority, and correspondingly of every kind of willingness to obey, is a belief, a belief by virtue of which persons exercising authority are lent prestige" (Weber 1964: 382).

Weber distinguishes among three main sources of legitimacy-understood as both the acceptance of authority and of the need to obey its commands. People may have faith in a particular political or social order because it has been there for a long time (tradition), because they have faith in the rulers (charisma), or because they trust its legality-specifically the rationality of the rule of law (Weber 1990 [1918];

Legitimacy is not justice or right in an absolute sense; it is a relative concept that exists in people's subjective perception. All regimes that are capable of effective action must be based on some principles of legitimacy. Some political economists believe that there is no such thing as a dictator who rules purely by force. A tyrant can rule his children, old men, or perhaps his wife by force, if he is physically stronger than they are, but he is not likely to rule more than two or three people in this fashion and certainly not a nation of millions.

When the opposition in Zimbabwe say that Mugabe is ruling them by force, what they mean is that Mugabe's supporters', including Zanu PF, the Central Intelligence Organisation and other state agents are able to physically intimidate them. But what made these supporters loyal to Mugabe? Certainly not his ability to intimidate them physically: ultimately it rest upon their belief in his legitimacy authority.

Security apparatuses can themselves be controlled by intimidation, but at some point in the system, Mugabe has loyal subordinates who believe in his legitimate authority. It is not always the case that a regime needs to establish legitimate authority for the greater part of its population in order to survive.

Already we can see the cracks from the likes of expunged and now squealing Didymus Mutasa. Mutasa was the Zanu PF Secretary for Administration before his expulsion for allegedly supporting the presidential ambitions of former Vice President Joice Mujuru. He reminds me of Squealer in George Orwell's Animal Farm. Every tyrant has his sycophants, and Napoleon had one in Squealer, a clever pig who (as the animals say) "could turn black into white."

We now get the confirmation from Mutasa that Robert Mugabe lost to Morgan Tsvangirai in the 2008 elections. A larger part of the population knew that Mugabe had lost, but Zanu PF dug its heels, knowing that it had the legitimacy from the securocrats and army generals.

A lack of legitimacy among the population as a whole does not spell a crisis of legitimacy for Zanu PF unless it begins to infect the elites tied to the revolutionary party itself, and particularly those that hold the monopoly of coercive power. The threat to Mugabe is the top Zanu PF brass, the armed forces and the police. When we speak of a crisis of legitimacy in the Zanu PF system, we are speaking of a crisis within the top elite whose cohesion is essential for Mugabe to act.

Where does Mugabe's legitimacy spring from? It could be from personal loyalty on the part of a pampered top brass or those who still believe in his ideology. His land re-distribution programme, has not gone unnoticed, albeit the devastating economic consequences that ensued.

The more we see purges going on in Zanu PF, the more Mugabe is losing his legitimacy. President Mugabe has been around long enough to suffer an internal crisis of legitimacy.

Some observers have labelled Zimbabweans as being too passive, fatalistic or endlessly melancholy. One thing these observers prefer to ignore is the fact that Mugabe is old and could have retired some time back. However, he cannot do so as long as the few thousand elites, powerful securocrats want him to stay put. They still see his legitimacy in power, for various reasons best known to them. Some of the reasons are quite obvious. Some of the Mugabe's close cabal have been enriching themselves by looting state resources. They are happy for the old man to stay at the helm, as long as they can keep their ill gotten riches. The moment these elites decide that enough is enough, Mugabe will not last.

Like so many called "strong man" of Africa, Mugabe will have to admit that he will eventually have to confront the fact that he has no long term legitimacy, and no good formula for solving the long term economic and political problems we now face.

Finally, revolutionary parties or one party rule tend to degenerate over time, and to degenerate more quickly when faced with a well educated, agitated and technologically advanced jobless youth. President Mugabe is a charismatic character. Revolutionary regimes may govern effectively in their early years by virtue of charismatic authority. However, with Zimbabwe facing a poor service delivery from the government, high rate of unemployment, lack of accountability, a dying industry, the legitimacy of the nonagenarian is always fading by the day. We shall hear more and more squealing from the revolutionary party.

Follow Tendai Kwari on twitter @tendaikwari