What are the essential differences between countries that succeed in becoming sustainable democracies, with growing economies, and those that don't? I spend a lot of time thinking about this question, because it is the DA's job to help ensure the long-term success of South Africa's transition. We know there have been more transition failures on our continent than successes. How can we ensure that South Africa does not follow the trajectory of cronyism, corruption and the criminal state?

All failed transitions begin with power abuse. A good constitution, on its own, cannot prevent this. Indeed, power abuse usually begins with an assault on the constitution -- and this can happen without changing a single word of it. It happens when rulers turn the independent institutions of the constitution into extensions of their power. We saw this happening, for example, when Vusi Pikoli was fired as National Director of Public Prosecutions (for refusing to withdraw corruption charges against Jacob Zuma), and was replaced by Menzi Simelane, a well-known Zuma ally who does not believe in prosecutorial independence.

If the constitution cannot, on its own, prevent us from becoming a failed state, what can?

The only guarantee of success is citizens who understand that they are personally responsible for preventing power abuse. These citizens understand the power of their vote and use it to protect the constitution and hold their leaders to account. Their leaders know that if they abuse power they will lose power. For a democracy to work, the politicians must fear the voters, not the other way around.

Voters in a consolidated democracy would never have allowed the rape of their prosecutorial authority. Developments like this show us how far we still have to go.

Are we moving in the right or the wrong direction? The signs are both good and bad.

On the positive side, citizens are increasingly using the power of their vote to change their public representatives through the ballot box. The results of some recent by-elections re-confirm this trend.

But there are also counter trends that we cannot ignore. Take Kannaland, a district municipality in the Karoo where a by-election was held recently. The winning candidate was the Jeffrey Donson, of the Independent Civics Organisation of South Africa. A former school teacher, Donson has long been known for his predilection for young girls. After leaving education for politics, he rose through the ranks to become Mayor of Kannaland. In 2008 he lost his council seat when he was found guilty and sentenced to five years in prison for the statutory rape of a 15 year-old girl. This was later reduced to a suspended sentence on appeal.

Three weeks later, Donson stood as a candidate in a by-election to get his seat back. The voters re-elected him.

Donson lost his seat again at the end of last year when he was found guilty of malpractice and corruption during his tenure as Mayor. Undeterred, he stood once again in the by-election to fill the vacancy that arose after his dismissal. And again, the voters re-elected him.

When this happens, what will deter politicians from corruption and power abuse? Nothing. Unless enough voters understand that it is their responsibility to hold power to account through their vote, the downward spiral towards the failed state can be as rapid as it is inevitable.

The accountability deficit is the biggest threat to our democracy.

It is not limited to small towns in the Karoo. It is the common denominator of governance across most of the country.

Limpopo has been much in the news this week because of the endemic corruption that is the inevitable consequence of the power abuse inherent in the ANC's version of economic empowerment. It is legalised corruption. It enables the ANC in government to award tenders to the ANC in business to enrich the ANC's leaders. That is how companies, of which Julius Malema is a director or major shareholder, got tenders to the value of R140-million. Three bridges they constructed washed away in a matter of months.

According to Sello Moloto, the former Premier of Limpopo, Malema "got those tenders by intimidating mayors and municipal managers that they would lose their jobs if they did not approve the appointments of his companies". Malema did this with the help of his ally Cassel Mathale who, as the ANC's Provincial Chairperson in Limpopo, had the power to appoint mayors and deploy municipal managers. Mathale himself is now Premier of this Province.

The mayors and municipal managers of Limpopo are obviously more frightened of Malema and Mathale than they are of the voters. Limpopo mayors believe that voters will continue to support the ANC whatever they do. On the other hand, the mayors know they will lose their jobs if they refuse to be complicit in Malema and Mathale's schemes. In other words, these mayors conclude that they will be in trouble if they refuse to be corrupt. Indeed, the only way to secure their positions is through corruption. If voters allow this, they have only themselves to blame.

This is precisely the opposite of how things should work in a democracy.

Malema expects to be re-elected unanimously as the President of the Youth League later this year, and from that point on he will continue his campaign for the country's top job. He believes he can reach his goal -- even though he treats voters with complete contempt.

He exemplifies the accountability gap.  He flaunts his millionaire lifestyle, with his R250,000 Breitling watch and R800,000 car, even as he proclaims he is a "humble man" as he did this week at his 29th birthday celebrations (which cost at least R400 000).

Speaking at his party, Malema said: "I'm still living in poverty today, because as long as a neighbour of mine is struggling, I too am struggling."

Without a hint of irony, he then popped the cork of an R800 bottle of Moet et Chandon champagne.

This perfectly captures the fundamental contradictions of the ANC under Jacob Zuma. While it pretends to be the voice of the poor, its ruling clique makes billions from state contracts. While it pretends to be the voice of the powerless, its leaders abuse their power for their own ends.

It is a kleptocratic elite masquerading as a political party.

And it happens because the majority of voters allow it -- even encourage it.

Jacob Dlamini, a columnist with Business Day, recently lamented the fact that newspapers expose major scandals, that are "here this week; gone the next". That is inevitable if the voters don't take follow up action at the ballot box.

While the freedom of the media is indispensible in a democracy, even the most vigorous press is not sufficient to sustain it.

It is time voters understood that no politician can continue to abuse power without their permission. Voters have the power to withdraw their permission through their vote.

It is our primary duty to get this message across if we want to secure South Africa's transition to democracy and prevent the failed state. We must do so, not because winning power is an end in itself, but because it is essential to establish the principle and practice of accountability in our young democracy. It is essential to address the accountability deficit.

If people do not like the alternative we offer, there is no shortage of others. For our part, we will continue to work day and night to make real our commitment to an "open, opportunity society for all" which we believe is the only alternative that can secure growing prosperity and freedom for everyone in South Africa.

This article by Helen Zille first appeared in SA Today, the weekly online newsletter of the leader of the Democratic Alliance

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