Jacob Zuma – the former deputy president of South Africa and stalwart of the ruling African National Congress – was cleared Monday of rape charges by a Johannesburg High Court. His trial had dominated headlines in South Africa and beyond, sensationalized by charges of corruption and political conspiracy, ethnic rivalries, and his accuser’s HIV-positive status. Though important in its own right, the outcome of the trial represents only a fraction of its significance, leaving in its wake a number of large and looming questions about the future of a liberal, democratic South Africa.

The first of these questions concerns the political maturity of the ANC governing alliance. The rape accusations against Mr. Zuma did not occur in a political vacuum. Rather, they came about during ongoing corruption proceedings against Mr. Zuma. While much of the evidence pointed to Mr. Zuma’s guilt – the solidly independent Durban High Court and vigorous national prosecutors had accused Mr. Zuma of complicity in arranging corrupt arms contracts – his many supporters in the ANC immediately painted Mr. Zuma a victim of a political conspiracy coordinated by President Thabo Mbeki, his “neo-liberal” allies in the ANC and the National Prosecuting Authority, and the “white-controlled” press.

These charges escalated after Mr. Mbeki sacked Mr. Zuma – widely considered his rightful successor by the ANC’s powerful left wing – and the rape accusation began circulating in local newspapers. Playing up both his credentials as an anti-apartheid hero and his Zulu roots, Mr. Zuma encouraged the idea that he was being punished for his revolutionary ideals and ethnic identity.

This narrative is important because of what it discloses about the political culture of the increasingly dominant – and, paradoxically, increasingly fractured – ANC. Mr. Zuma’s supporters, drawn primarily from the ANC Youth League, the South African Communist Party, and the South Africa Confederation of Trade Unions, represent a core of black South Africans disenchanted with the pace of economic “transformation” in their country and hungry for a more radical approach to wealth redistribution than Mr. Mbeki’s measured, market-based strategy. While the rape charges saw official support for Mr. Zuma decline, many of his popular supporters have displayed an outright disregard for the rule of law and a proclivity for violent rhetoric – the anthem of Mr. Zuma’s camp is the revolutionary standard “Awuleth’ umshini wami,” or “Bring me my machine gun.” And while these South Africans have legitimate grievances, the means being advocated to redress them are similar enough to those employed in neighboring Zimbabwe to cause fright. Given the centrality of Mr. Zuma’s supporters to the ANC’s political dominance, the emergence of a more radical, anti-democratic party is a realistic possibility.

So too is the rekindling of political violence in South Africa. Ethnic tensions underscore the entire Zuma affair. Much of the “evidence” for a political conspiracy to oust Mr. Zuma revolves around the fact that he is a Zulu, while Nelson Mandela and Thabo Mbeki – as well as a large segment of the ANC leadership – are Xhosa. Thus, Mr. Zuma is portrayed as the victim of a Xhosa plot to keep a Zulu from becoming president of South Africa, a claim that Mr. Zuma has explicitly encouraged by giving all testimony in Zulu and defending his sexual actions based on traditional Zulu male “responsibilities.” Mr. Zuma is described by many of his supporters as the “100% Zulu boy.” Remembering the gruesome political violence between the ANC and Zulu nationalists that marked South Africa’s democratic transition, the militant tribalism displayed by some of Mr. Zuma’s supporters is worrying.

Just as significantly, the trial disclosed frightening questions about the level of tolerance for violence against women and a continuing – and fatal – ignorance about HIV/AIDS in the South African polity. Regardless of the trial’s outcome, the treatment of Mr. Zuma’s accuser by his mass of supporters was abominable, including a barrage of verbal (and highly misogynist) abuse, attempted physical attacks, and deaths threats, behavior that speaks to South Africa’s claim to one of the world’s highest rates of sexual assault. (Indeed, the South African police, citing fears for the accuser’s life, are encouraging her to leave the country.) What’s more, much of Mr. Zuma’s defense reinforced traditional views of women’s rights and sexual mores out of step with a modern, democratic society.

Of further concern was Mr. Zuma’s cavalier attitude toward contracting HIV/AIDS, a disease that infects over 6 million South Africans and is responsible for one of three deaths in the country. Acknowledging that he was aware his accuser was HIV-positive, Mr. Zuma – once the head of the South African National AIDS Council – testified that he did not fear infection because he showered after having (consensual) intercourse. While Mr. Zuma’s message to his fellow South Africans could not have been worse, it should have come as no surprise from such a high-ranking politician: The government’s fecklessness in the face of the deadly pandemic is well-known.

The splitting of the ANC alliance is not inherently dangerous for South African democracy; in fact, it would be a welcome development should it produce a realistic, democratic opposition. However, the Zuma trial has revealed a conceivably ugly alternative: a radicalized, ethnicity-determined schism led by politicians representing retrograde attitudes toward women and a willful ignorance about HIV/AIDS. The cleavages exposed by the Zuma trial pose potentially serious challenges to South Africa’s democratic future.

Mr. Rosenberg is researcher at Freedom House (www.freedomhouse.org) and assistant editor of Freedom in the World. He serves as Freedom House’s Southern Africa analyst.