Revolts within political parties can sometimes lead to changes more radical than those brought about by general elections. One of the best examples was when a revolt against PW Botha at the top of the National Party brought FW de Klerk to power and started the process which led to the handover of power to the ANC.
With bold leadership, even one-party states can undergo radical reform, as we saw with Deng Xiaoping in China in the late 1970s and Mikhail Gorbachev in the Soviet Union a decade later. This is not an argument for one-party states, to which there are fundamental objections, but merely to highlight a historical fact. Nor do changes of government necessarily lead to much reform: after the Second World War, the United Kingdom was ruled by a consensus between government, business, and labour, irrespective of whether the Conservatives or Labour were in power. It was not until Margaret Thatcher became prime minister in 1979 that the consensus was broken by radical reform.
At this stage, a week after the meeting of the national executive committee (NEC) of the African National Congress (ANC), it is impossible to say whether the revolt against President Jacob Zuma has peaked. But it is still worth asking how fundamental a difference his departure would make. Would it indeed "save" South Africa, as some suggest?
There are three broad issues to consider. The first is corruption, the second is state capture, and the third is policy. The main reasons for the revolt against Mr Zuma in the ANC are the first two of these, not the last.
Given the risks that failure to deal with corruption will pose to the ANC at the general election due in 2019, it is likely that the party will require whomever replaces him to try to root out that problem. This will be enormously difficult given that corruption is not the exception but the norm at all levels of government and among numerous state-owned entities.
Few challenges are likely to be tougher than freeing the state's security services, including the intelligence, police, and prosecuting authorities, from political capture. They are capable of skulduggery that goes beyond financial malfeasance. Establishing them as independent organisations will require not only courage and integrity, but also political skills of the highest order.