Nigerian President Olusegun Obasanjo's first priority following his re-election will be to convince doubters that his new mandate is legitimate.
This will not be an easy task, as supporters of his main challenger, Muhammadu Buhari, refuse to accept the results, saying the vote was rigged.
But observers say that Mr Obasanjo does enjoy considerable support and probably would have won the election, even without the "over-zealousness" of some of his supporters.
According to the official results, he polled twice as many votes as Mr Buhari - a difference of 12 million.
This is far more than were cast in the states in the south and east, where the worst irregularities occurred.
'Long list of things'
If he does manage to calm the tempers of those who feel aggrieved, however, he may well ask himself what he has let himself in for.
Mr Obasanjo has been re-elected for a second four-year term
Supporters of Mr Obasanjo and Mr Buhari do agree on one thing - life in the world's sixth largest oil producer should be better.
"We need jobs, roads, electricity, water, schools and clinics," everybody said as they queued to vote.
They were just divided on who was better placed to solve these problems.
"He has a long list of things to do. He tried in his first term, but now he must do more," says Tony Amadi, author of a book on Mr Obasanjo's People's Democratic Party, The Making of the PDP.
Nigeria's most pressing problems include:
Insecurity- several thousand people have been killed in ethnic and religious violence since military rule ended in 1999
Corruption - Nigeria is frequently ranked the world's most corrupt country by campaign group Transparency International
Poverty Alleviation - some 66% of the population live on less than $1 a day - a similar figure to poor African countries which are not blessed with oil
Economy - Nigeria is heavily dependent on exports of crude oil, while agriculture and industry are declining
Looking 'beyond oil'
"To leave a legacy in four years, he must shake up the economy of the country," Mr Amadi says.
Nigerian oil is crucial to the world market
Analysts agree that a priority is to build oil refineries. Nigeria exports some 1.86 million barrels of crude oil a day but then imports the refined product at a far higher price.
Exporting refined oil would earn far more foreign currency and having more domestic refineries should also end the chronic fuel shortages which plague Nigeria.
But economists say that Nigeria must start to look beyond oil.
"I don't know what our policy planners are doing," says Nazeef Abdullah from the Economics Department at the University of Abuja.
"We must strengthen agriculture and industry."
Nigeria's fault lines
Some 65% of Nigerians live in rural areas. Many are subsistence farmers, who inhabit a different world from the gleaming new air-conditioned buildings and four-lane flyovers of Abuja.
Putting money into agriculture would be one of the best ways of raising the living standards of the very poorest Nigerians.
34% illiteracy rate
38% no access to safe water
6.8 computers/1,000 people
Source: World Bank
Mr Abdullah says that the key to ending chronic insecurity is to adequately fund and equip the police.
A lack of faith in the police is one reason behind the growth of ethnic militias across the country.
Long-running arguments over the distribution of oil wealth are another factor behind ethnic unrest.
Residents of the oil-producing Niger Delta region say their oil has built Abuja and Lagos and now they are demanding, sometimes violently, their share of the oil bounty.
Muhammadu Buhari refuses to accept his defeat
During his first term, Mr Obasanjo set up the Niger Delta Development Commission (NDDC) to plough some oil money into roads, schools and training for the region's inhabitants.
In two years, the NDDC has spent some 40 billion naira ($28m) but Delta inhabitants say they have not seen where the money has gone.
But Mr Abdullah points out that if Mr Obasanjo devotes too much attention to the mainly Christian south, where he gets most of his support, he risks being seen as a southern president.
Most northern, Muslim-dominated areas voted for Mr Buhari and alienating them even further would risk worsening ethnic and religious tensions.
Clashes between Muslims and Christians have seen some of the bitterest fighting of the past four years.
When Mr Obasanjo came to office in 1999, he promised to vigorously fight corruption, which has plagued Nigeria for so long.
But only one minor official has been prosecuted by his anti-corruption commission.
This is yet another priority for his second term, although getting tough would take considerable political courage as corrupt politicians, from whichever party, would no doubt seek to go down fighting.
So is he up to the task?
Mr Amadi says he must purge his cabinet of some of the "deadwood" in order to breathe new life into the government.
"He wants to leave a legacy. He cannot blow it by failing this time," he says.
His supporters say that he was just being cautious in his first term for fear of stepping on too many toes and risking a return to the dark days of military rule.
They say he will now show his true colours and take action to improve the lives of the 129 million Nigerians.