ONE can be forgiven for thinking that Joice Mujuru, the former vice-president, is the most popular figure in Zimbabwe. And up to a point that would be right. Her picture regularly appears on the front pages of local newspapers, and she does have many supporters. She may even have more than anyone in the ruling ZANU-PF party apart from Robert Mugabe, the president, who continues to enjoy significant acclaim despite political repression and a worsening economy.

Yet the reason Mrs Mujuru features so regularly in the papers, especially those controlled by Mr Mugabe, is a campaign to vilify her that has continued even after she was sacked in December. The Herald newspaper, a party mouthpiece, calls her “the putschist” in reference to allegations that she tried to seize power, a claim she firmly denies.

Until last year Mrs Mujuru was one of two potential successors kept around by the 90-year-old president. Then in August his wife, Grace, an unpopular 49-year-old former typist, began denouncing her in public. For a while the president watched from the sidelines, giving rise to suggestions that Lady McGabe, as she has become known, may succeed him, or at least that she aspires to do so.

The most immediate beneficiary of the shuffle, however, was the other possible heir, Emmerson Mnangagwa, the defence minister, who was given the vice-presidency. Aged 72, and lacking the popularity of the 59-year-old Mrs Mujuru, he is less of a threat to the president who must surely hear time’s winged chariot drawing near. Interlocutors say Mr Mugabe has a sharp mind but slumping limbs; the nonagenarian spent more than a month with his doctors in Singapore over Christmas.

Still, why continue the vilification of Mrs Mujuru now? Having been turned into an enemy but left in the party, she is a threat to the Mugabes more than ever. She could step forward at some point to challenge one or other of them when the party chooses a nominee for presidential elections. As a former guerrilla, she has unimpeachable liberation credentials. She could also make other mischief. She is already preparing the ground by challenging her dismissal in the courts—a hopeless undertaking on the face of it, since the president controls the judiciary, but one that may plant the seed of her return.

So the attacks on her continue, though they create their own risks. Baited and pushed out of Zanu-PF, Mrs Mujuru and her supporters could make common cause with the opposition—which otherwise appears to have hopeless prospects—thus reigniting competitive politics in the country. Morgan Tsvangirai, the leader of the opposition Movement for Democratic Change, is thought to be keen on the idea of an alliance, having lost an election in 2013. “Grace and Emerson would be no match for Joice and Morgan,” says one insider, referring to a post-Bob election.

How far the Mugabes will go in tormenting their former vice-president remains to be seen. The answer may lie in the political ambitions of the first lady. Mrs Mugabe tasted political power last year during a cross-country speaking tour in which her fiery denunciations prepared the way for Mrs Mujuru’s dismissal. If Mrs Mugabe is serious about one day seeking the presidency, she may try to eliminate her rival once and for all by driving her out of the ruling party.

A first clue will come in parliamentary by-elections due to be held in coming months. Mrs Mugabe may run, which would make her eligible for a cabinet post if she is successful. The top job at the ministry of gender affairs has, conveniently, been kept open by her husband.

-The Economist