Jobless graduates, struggling business owners and army veterans marched through the eastern South African city of Pietermaritzburg this week, chanting the name “Jacob Zuma.”
The 500 or so demonstrators brought to a standstill parts of the city, in KwaZulu-Natal Province — the traditional stronghold of Mr. Zuma, a past president of both South Africa and the African National Congress, the party that governed the country for three decades.
Demanding water and electricity, the protest over commonplace local concerns was also a show of power for the new political party that Mr. Zuma now leads — uMkhonto weSizwe, or M.K. — with the hope of eroding the dominant position of his former allies.
“We are going to have to fight for things to change,” said Khumbuzile Phungula, 49, who joined the march after her neighborhood went weeks without water. “M.K. is all about change.”
As vendors sold Jacob Zuma T-shirts and an M.K.-branded energy drink, and men in the military fatigues of long disbanded anti-apartheid movements marshaled the crowd, the marchers embodied Mr. Zuma’s new party: a group of aggrieved voters who, like him, have fallen out with a governing party they view as ineffectual and corrupt. Mr. Zuma’s supporters now form a bloc large enough to turn him into a potential kingmaker in South Africa’s general election on May 29.
Not present at the Pietermaritzburg march was Mr. Zuma himself. Instead, he was preparing for a hearing at South Africa’s Constitutional Court on Friday about whether Mr. Zuma, 82, is eligible to stand at all. He resigned from the top office in 2018 amid widespread protests, and three years later was convicted and sentenced for failing to appear at a corruption inquiry, though in the end he served only two months of a 15-month sentence.
Mr. Zuma is also already facing factional battles within his budding party: A senior M.K. leader has accused the party of forging the signatures needed to contest the election, and the police say they are investigating the claims, which Mr. Zuma has dismissed as a baseless smear.
Yet neither of those potential obstacles has deterred M.K. party members or diminished Mr. Zuma’s status as a political threat. A lower court has already ruled that he can run for office, and M.K. plans to turn his next court appearance into a campaign event in which Mr. Zuma is expected to address his followers.
Both Mr. Zuma and his party have quickly gained momentum, capitalizing on the A.N.C.’s internal leadership squabbles and its failure to provide basic services for South Africans. Since its founding just five months ago, M.K. has upended the country’s political landscape and become one of the most visible opposition parties in a crowded arena.
Though he led the party they now blame for the country’s troubles, Mr. Zuma’s supporters look back at his decade in office with nostalgia, including many of those at the demonstration in KwaZulu-Natal, the country’s second most populous province.
Lucky Sibambo, a forestry engineer who described himself as a political spectator before the launch of M.K. and who helped mobilize the march, said he believed Mr. Zuma’s support for expropriating land without compensation and redistributing it would help Black businesses like his.
Sphumelele Mthembu, 28, said she had been unable to find a paying job despite having a postgraduate degree in clinical psychology. “We’re done with the A.N.C.,” she said, watching the march from the balcony of a youth training center. “We’re tired of the lies, the money going missing.”
And Mnqobi Msezane, 34, who has been drumming up support for Mr. Zuma on university campuses, cited his promises of free college education. Mr. Msezane dismissed the corruption accusations that dogged the former president’s tenure as a political ploy to thwart Mr. Zuma in challenging the Black political elite and ending the economic dominance of white South Africans.
“Poverty has a color to it, and it’s Black,” Mr. Msezane said.
Mr. Zuma has turned his court battles into fodder for campaign speeches claiming political persecution, and his supporters have rebranded the controversies of his presidency as tales of success. But even as his popularity has helped the M.K. party grow, the scandal-prone former president also has liabilities as a party leader, Mashupye Herbert Maserumule, a professor of public affairs at the Tshwane University of Technology in Pretoria, said in an interview.
It is clear each time Mr. Zuma addresses a crowd that his personal gripes shape the party’s policies, Mr. Maserumule said. Mr. Zuma has, for example, called for judicial change, an echo of his repeated claims that he is a target of the courts.
And, he added, “If he’s no longer the face of M.K, that will also mark the end of M.K.”
But so far the M.K.’s growth has eaten into support for older opposition parties, like the Democratic Alliance — the country’s official opposition — and the Economic Freedom Fighters. One former councilor for the Democratic Alliance, Shawn Adkins, a pastor, even said he had decided at the Pietermaritzburg march to defect to the M.K., fed up with the slow rollout of housing in his neighborhood. “I’m convinced,” Mr. Adkins said.
Support for the A.N.C. has been declining for years, and facing a clear threat from the M.K., the governing party is meeting its new rival head-on.
The A.N.C. recently deployed its senior leaders and alliance partners for what the party called “a week of intensive campaigning in KwaZulu-Natal,” in an effort to ingratiate itself with voters there. Alongside hundreds of volunteers, prominent A.N.C. figures fanned out across the province, foregoing large rallies for more personal home visits.
“We are actually going all out to talk to people, to say to them that the A.N.C. still exists, the A.N.C. is still strong, it’s still worth supporting,” said Dr. Zweli Mkhize, a former A.N.C. provincial chairman and presidential candidate who was campaigning in Pietermaritzburg’s Eastwood township.
Their efforts paid off with some locals.
One voter, Queenie Potgieter, 65, said that she would have supported M.K. if the A.N.C. had not “warmed” her home, but that a visit by Dr. Mkhize had changed her mind.
And as Dr. Mkhize handed out T-shirts and sarongs in the party’s colors, Tusiwe Mkhabela, a 21-year-old first-time voter, burst into tears at the sight of a man she considers a celebrity. The A.N.C. has provided her family with welfare and food parcels, she said, and she believes they will also secure a job for her.
Yet Annaline Merime, 28, who has never voted, dismissed the A.N.C. stalwart with a side eye. “Only when it’s time for voting do they do this,” she said. “Where are they the rest of the year?”
Dr. Mkhize said that the A.N.C., aware of its own failures, would not underestimate Mr. Zuma’s support in the province, or the voters’ frustration. It was under Mr. Zuma that the A.N.C. itself grew in KwaZulu-Natal, and it was Mr. Zuma who groomed the province’s current leaders, Dr. Mkhize said.
Noting that the A.N.C. has dealt with breakaway parties before, Dr. Mkhize said he remained cautiously confident.
“The only complication for us is that we’ve never had President Zuma campaigning on the opposite side,” he said.
