(Bloomberg) -- The floodgates have opened. At least 12 challengers are bidding to defeat Nigerian President Muhammadu Buhari in February’s elections, but their sheer number will strain the opposition’s ability to unite behind a single candidate to stand a chance of winning.

With the president of Africa’s biggest oil producer facing discontent over security crises and an anemic economy, top candidates including Senate President Bukola Saraki, former Vice President Atiku Abubakar and ex-Kano state Governor Rabiu Kwankwaso are defectors from the ruling party. The danger that they’ll switch allegiance again if they don’t win the nomination could be one of Buhari’s trump cards.

The answer will come after the People’s Democratic Party’s nomination convention in October, when one candidate emerges and the other challengers decide whether to back him or strike out on their own and split the opposition.

“Any fractious nomination process and attendant discontent delivers the election to Buhari’s ruling All Progressives Congress effortlessly,” said Idayat Hassan, executive director of the Abuja-based Centre for Democracy and Development. “Time is not on the side of the opposition -- less than six months into the elections, they have no candidate.”

Buhari’s Nomination

With Buhari so far the APC’s sole candidate, the party’s convention next month is expected to be a coronation of the president. The PDP conclave could be the make-or-break moment for the election in Africa’s most populous nation.

Most of the candidates have said they’ll support whoever emerges as winner. The 71-year-old Abubakar, who’s been a candidate for three different parties since Nigeria returned to democratic rule in 1999, has vowed to stick with the PDP if he fails to win the nomination. But he’s already facing resistance within the opposition, with former President Olusegun Obasanjo saying he wouldn’t support his former deputy.

Assurances of loyalty could face severe strain given the egos and personalities seeking the nomination, according to Moses Ochonu, a professor of African history at Vanderbilt University in Nashville, Tennessee. Yet the PDP candidates know that unless they put their differences aside, they’ll stand little chance of defeating Buhari, he said.

“Perhaps the candidates’ collective fear of a Buhari second term would be enough to heal the injuries that will inevitably result from such a crowded contest,” Ochonu said.

The defectors were part of a coalition that propelled Buhari to become the first opposition candidate in Nigeria’s history to win power through the ballot box. He swept to office three years ago pledging to stamp out widespread graft, crush a raging Islamist insurgency in the northeast and reduce’s the economy’s dependence on oil.

While the security forces have made some progress against the militants known as Boko Haram, a breakaway group, Islamic State West Africa, is gaining influence. In the central region known as the Middle Belt, competition for grazing land between mainly Muslim herders and Christian crop farmers has sparked the nation’s deadliest conflict this year.

Abubakar’s ‘Deservation’

The Nigerian leader has also faced criticism that his graft war is targeting mainly political opponents and that his earlier policies, particularly restricting foreign exchange, pushed Nigeria into a recession in 2016 following the oil-price crash two years before.

“Many people are convinced the incumbent is ineffective and hasn’t delivered,” Clement Nwankwo, executive director of the Abuja-based Policy and Legal Advocacy Centre, said in an interview. “So the candidates fancy themselves as better options for Nigeria.”

Senate President Saraki, 56, has emerged as a front-runner, highlighting his relative youth compared to Buhari, who spent a total of five months in the U.K. last year for treatment of an undisclosed ailment. Abubakar has emphasized his business and political experience, with his campaign posters blaring “Deservation,” meaning he deserves it.

Aminu Tambuwal, the governor of Sokoto state in the northwest, is increasingly seen as a potential surprise nominee. The region, home to 26 percent of registered voters in 2015, backed Buhari in that year’s election and is the home of Sultan Abubakar III, the spiritual leader of Nigeria’s Muslims, who constitute roughly half of the nation’s population.

The president’s standing in the area has suffered because of his government’s continued detention of former national security adviser Sambo Dasuki, a member of the Sokoto royal family, on corruption allegations in defiance of court orders to free him on bail.

Tambuwal, 52, also appears to enjoy the backing of Nyesom Wike, the governor of oil-rich Rivers state in the south whose candidates won key party positions at the last convention in December, according to Amaka Anku, Washington D.C.-based Africa analyst for Eurasia Group.

Whoever emerges as the PDP nominee, his chances will depend on opposition unity.

“Can they keep it together after the primaries? The ability to unite behind the ultimate candidate is absolutely decisive for this election,” Anku said. “I think there’s enough people in the PDP who realize that this is critical to their chances of winning the election.”

(Adds share of northwest voters in fourth paragraph below Abubakar’s Deservation subheadline.)

To contact the reporters on this story: Dulue Mbachu in Abuja at dmbachu@bloomberg.net;Yinka Ibukun in Lagos at yibukun@bloomberg.net;Solape Renner in Lagos at srenner4@bloomberg.net

To contact the editors responsible for this story: Karl Maier at kmaier2@bloomberg.net, Karl Maier, Michael Gunn

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