With many northern states rallying behind primary challenger Gen. Muhammadu Bahari, President Goodluck Jonathan and his long-ruling People’s Democratic Party are expected to face post-election violence and deepened distrust over the electoral process if he is reelected for a second term in Nigeria's presidential election on Saturday. The opposition All Progressive Congress party and its supporters are expected to dispute the election results after polls have predicted the tightest presidential campaign in Nigerian history.

“The possibility of a disputed outcome is very much there and it could be very dangerous,” said Jennifer Cooke, director of the Africa Program at the Center for Strategic and International Studies (CSIS) in Washington. “If there are allegations of rigging – even if it’s unproved – political tensions are so high and polarization is so deep right now, that could very well lead to violence.”

Allegations of ballot rigging is a dangerous narrative in Nigeria’s presidential election, and Jonathan is no stranger to such accusations. Jonathan secured an outright victory in his last presidential election against Buhari, a former military dictator, by winning about 59 percent of the vote. But the win was hotly contested in the north and post-election violence killed 800 people in 2011 and 75,000 others were forced to flee their homes.

Last month, Jonathan decided to postpone the presidential election from February 14 to March 28 because the Nigerian military said it couldn't ensure voter safety, particularly in the northeast, where Boko Haram militants have taken hold. The delay prompted further suspicion from Jonathan's critics of vote rigging.

But security forces have claimed some success against the terror group in the last six weeks, and electoral officials said they have had more time to distribute voting cards. As of Tuesday, about 82 percent of registered Nigerian voters had collected the cards required to take part in Saturday's election, Reuters reported. Attahiru Jega, chairman of Nigeria's Independent National Electoral Commission, said the commission is fully prepared and nothing can stop it from holding “flawless or near perfect elections” this year, the Daily Post in Nigeria reported. 

Life in northern Nigeria has changed little under Jonathan. Electricity access remains limited and many people still live in mud and thatch houses. Modern energy sources are needed in these rural areas to improve health, education, transportation and commercial development, according to the Solar Electric Light Fund, a Washington-based nonprofit.

Jonathan, a 57-year-old southern Christian from the petroleum-rich Niger Delta region, could stifle post-election violence in the north by providing the region with real economic benefits such as building roads, raising incomes and improving electricity. Jonathan must also address the national security crisis by continuing to eliminate the Boko Haram insurgency in the northeast, which has killed and displaced thousands of Nigerians.

“He’s going to have to do more than tokenist public appearances,” said Darren Kew, an associate professor of conflict resolution at the University of Massachusetts Boston and the executive director of the Center for Peace, Democracy and Development.

Nigeria is Africa's largest economy and lead oil producer, generating about $70 billion in state revenue each year -- more than two-thirds of which comes from exports in gas and oil. But very little revenue trickles down to help the rural population because more than 70 percent of the federal budget is spent on the salaries and benefits of a million public officials. Nigerian lawmakers make up to $2 million a year, according to Bloomberg News.

Critics have argued that government corruption has worsened under Jonathan's administration, and Nigerian lawmakers are in politics to get rich rather than improve the welfare of the Nigerian people. Nigeria's president plays a decisive role in dispensing state revenue, and both Buhari and Jonathan have pledged to combat corruption. 

Buhari, a 72-year-old northern Muslim, has publicly spoken against violence and voiced his support for a peaceful election. But it's unclear if that will prevent tensions from escalating in the predominately Muslim north and the predominately Christian south if Jonathan wins a second term. However, experts said localized upheavals are likely no matter the outcome of the election.

"Our hope is that there will not be any (violence). But political history shows there will be," said Jideofor Adibe of Nasarawa State University in Nigeria.