Far more will be at stake over the coming months than who our next president will be.

Whether democracies survive ­ and how they turn out ­ depends on how they deal with their tests.

That they will be tested is inevitable. The idea that governments should face limits on their power because they govern on behalf of the people does not come automatically to power holders. It can become habit.

But where, as here, the habit has not yet formed, it is not assured that when those who hold office are faced with the need to accept limits on how they govern, they will. If they do, democratic habits begin to form. If they do not, democracy may remain elusive.

That is why reaction to the Schabir Shaik judgment is so important.

Deputy President Jacob Zuma is hardly the first politician to be accused of taking payments from arms companies. All around the world, corruption and arms deals seem inseparable companions. Ministers and heads of government have been forced from office by their dealings with companies that sell arms.

But here far more is at stake. The idea that courts should hold to account political high-ups ­ in this case, the deputy head of state and frontrunner for president ­ is not a hallowed South African tradition: it charts a completely new course. And, as we have seen in the few days since the judgment, there are severe pressures against ensuring that the deputy president accounts before an open and independent legal process.

It has been clear for many months that a judicial finding that impugned Zuma would be widely rejected by his supporters. Where politicians are seen by those who support them as victims of the establishment, being accused of wrongdoing can increase their popularity because it may be seen as further evidence of their victimisation at the hands of those whose power they threaten. This has happened at times in the US: here and now, the deputy president benefits from it.

And in divided societies the identity of a judge may count for more than the quality of the judgment ­ inevitably, supporters of the deputy president have pointed out that the judge who found a corrupt relationship between him and Shaik is a white former Rhodesian cabinet minister.

So it is hardly impossible that the deputy president will not be called to account, but will be elected president without an open and independent hearing, on the support of the many who see him as a victim of the elite.

If that happens, democracy will have failed a crucial test. If some do not have to account for their actions because of who they are or how much support they have or who happens to preside over a court case, why should anyone in power account?

And so it may take a long time for democracy to recover if the deputy president’s role is not tested in an open and fair judicial hearing which will decide his political future.

In that case, we may also see a strong revival of “the politics of the back alley” in which untested allegations of corruption become weapons of political war and are rarely if ever settled by open legal processes. The progress we have made in ensuring that allegations are settled by openly weighing evidence will be lost.

But this is not inevitable. There are also pressures in the opposite direction. They vary from government’s desire to refute the prejudice that African governments are always corrupt and unaccountable, through its wish to be respected by major economic powers, through to the possibility that powerful figures within the African National Congress (ANC) do not feel that Zuma should be our next president and find the Shaik judgment a convenient instrument in their attempt to prevent this. (It is not always clear which power holders the deputy president’s supporters think he is a victim of ­ the white establishment or the ANC leadership).

Democratic principle is not always established by high-minded politicians whose values prompt them to do the right thing: indeed, around the world, that is the exception.

More often, democratic habit is created by what the philosopher Machiavelli called “fortuna” (circumstances), which happily make the democratic choice the favoured one.

Or it may be established by leaders who are smart enough to realise what is in their long-term interests, whatever their immediate preferences may be.

That mix of favourable circumstance and intelligent calculation may yet ensure that the deputy president’s guilt or innocence are tested and his political future decided by the result, establishing the habit, unheard of in our political history, that those who govern accept that they do so only as long as they act for the people rather than themselves.

As we watch these events unfold, it is worth bearing in mind how much is at stake.

Friedman is senior research fellow at the Centre for Policy Studies.

With ackowledgements to Steven Friedman and Business Day.