It was with deep a sense of irony that we saw President Jacob Zuma delivering a lecture on the unifying political life of Nelson Mandela, even as a political storm erupted in violence outside the church where he was speaking, resulting in scenes of children as young as seven being chased down the road by gun-wielding police officers.

Zuma was delivering the centenary lecture on Mandela, South Africa's first democratically elected president, at the Worship House Church in Thohoyandou, Limpopo on Tuesday .

He stood before a crowd, many of whom the ANC had bused in from his strongholds in the KwaZulu-Natal and Mpumalanga provinces, relaying the incredible story of Mandela, who despite his imperfections is world renowned as a principled unifier.

This was while the divisions in the ANC were on display in a most dramatic fashion outside the venue, in scenes reminiscent of the apartheid era.

Hundreds of security forces including those from the South African Police Service's riot unit, members of the National Intelligence Agency, the MKMVA, and private security were stationed inside and outside the church. Stacks of barbwire fence made up a steel wall fortress around the area.

Those who were barred from entering the lecture hall, many whom were ANC and ANC Youth League members, and other inquisitive locals who gathered to get a glimpse of the president, were attacked with water cannons and tear gas as police officers, carrying R5 rifles, chased after the unwanted guests shouting: "Voetsek, jou hond [Clear off, you dog].

A Nyala patrolled the entrance, at times jerking in towards the crowd. Two provincial youth league leaders were assaulted while dozens more (accredited) members of the local ANC branches were removed or prevented from attending the lecture.

The drama started inside the hall when a group of ANC and youth league members began singing in support of Deputy President Kgalema Motlanthe, while another group sang political praises for Zuma. The former group were chucked out because they were allegedly disrupting the lecture, which had not yet begun.

The Mandela lecture was meant to have been an opportunity for Zuma to reassert himself as a unifier, following in Mandela's footsteps. Instead, Zuma failed to show any leadership, and pretended that the violence outside did not exist. He continued with his speech uninterrupted, before being whisked out and away by his security team.

If he were indeed cut from the same cloth as Mandela, Zuma would have put his sensitive ego aside and marched outside to speak to them, and to listen. If anything, his aloofness only confirmed his detractors' views that he lacked backbone and true leadership instincts, and was incapable of uniting the ANC – something he had promised to do.

It's been less than five years since Zuma stood on the podium at the close of the ANC's watershed Polokwane conference. Emboldened by his victory over Thabo Mbeki and by the confidence and support of the party's branches, Zuma said: "This is not the time for the luxury of division and disunity at all levels … In every walk of life, we must close ranks".

In the run-up to the Polokwane conference, Zuma's successful campaign centred on him moulding himself as a Madiba-like unifier. Zuma punted himself as the comrade who would unite the various warring factions of the ANC and alliance partners. During his first speech as ANC president in 2007, Zuma referred to and quoted Mandela at length as he cashed in his winning campaign ticket.

He said: "Our father, stalwart and icon, Isithwalandwe Comrade Nelson Mandela outlined the importance of unity eloquently in a message to the ANC in exile after the 1976 uprising. He said: 'Every effort to divide the blacks, to woo and pit one black group against another must be vigorously repulsed. Our people – African, Coloured, Indian and democratic whites – must be united into a single massive and solid wall of resistance, of united mass action'."

"In a message sent to the ANC during the Kabwe conference, Madiba again reminded us that unity is the rock upon which the ANC was founded. This message was relevant then, it is still relevant to us today. We have to confront the issue of unity in the same manner that Madiba instructed the ANC in 1976 and 1985," continued Zuma.

In delivering the Mandela lecture on Tuesday, Zuma did so without the blessing of some senior members of the Mandela family who boycotted the event. Mere hours before Zuma's address, news broke that ANC stalwart Winnie Madikizela-Mandela had written a scathing letter to the ANC expressing the family's disappointment in the "shoddy" manner in which the party had treated Mandela and the family over the years. She charged that the ANC only ever cared about Mandela when it needed him to pursue its own "agenda".

"No one has cared to establish how we are doing as a family. It is quite clear that we do not matter at all, we only do when we have to be used for some agenda," said Madikizela-Mandela.

Zuma visited Mandela at home on Wednesday to wish him well for his upcoming birthday. However, all indications suggest that Zuma has failed to live up to his commitment of pursuing a united ANC – in the interest of all South Africans and Africans. The outburst outside the church was a symptom of the increasing anger many comrades are feeling towards him.

The brute show of force by the police raises more questions.

What exactly were Zuma and his organisers defending him from? Death threats? Detractors who are armed with unflattering songs and hand signals?

The fact remains that all the security in the country cannot protect Zuma from the threat he poses to his own ambitions for a second term. Through his unwillingness to listen to dissenting views, his apparent inclinations first towards those closest to him and his sidelining of his detractors he has made too many political enemies too soon.

It took the ANC almost a decade to reach the levels of frustration with Mbeki than what we are witnessing towards Zuma today – and this only 55 months into his term. And all the while Zuma's possible challenger, Motlanthe, has been quietly and diligently at work positioning himself as a leader who has the interest of the party at heart first and foremost … as someone who has what it takes to save the party from implosion. He has been projecting himself as a leader who is willing to listen and advise instead of ignoring and sidelining.

On Wednesday Talk Radio 702 host John Robbie put a question to Motlanthe: Will there be blood on the walls at the conference in Mangaung in December, or will the ANC come right?

Motlanthe, who was speaking from the politically historical Liliesleaf Farm in Rivonia, which was once the headquarters of Umkhonto weSizwe and where Mandela and others were arrested before the Rivonia Trial, said: "We've got to come right. I don't think there's any choice other than to set things right."