Not even an official inauguration can put an end to a political controversy in the West African nation of Ghana, where the opposition party has endangered stability in the country by refusing to accept the results of a closely fought vote.

On Monday in the capital city of Accra, incumbent President John Dramani Mahama was sworn in to serve four more years at the helm of one of Africa’s most successful democracies. Mahama represents the National Democratic Congress, or NDC, which also won a majority of the seats in parliament.

“I will do my best, I will give of my best, and I will ensure that my actions make a positive difference in the lives of Ghanaians,” he said after taking the oath of office.

Top officials from the opposition New Patriotic Party, or NPP, were notably absent from the ceremony. Their candidate, Nana Akufo-Addo, lost the presidential election by a scant 1 percent of the popular vote, and he has so far refused to accept the legitimacy of Mahama’s victory.

The NPP published an angry message on its website shortly after election results were first announced in December.

“It is obvious from the preponderance of evidence available to us that at all material times the ruling National Democratic Congress led by President John Mahama conspired with certain [electoral commission] staff in constituencies across the country to falsify the election results and thereby abuse the mandate of the people of Ghana,” said the statement.

But the results of the national vote have been confirmed by the Coalition of Domestic Election Observers -- a widely respected organization -- as well as the Economic Community of West African States, a regional body.

In short, the NPP doesn’t stand much of a chance at reversing the results of this pivotal election -- but it’s easy to see why they’re trying so hard.

“This was Nana Akufo-Addo’s last chance at the presidency,” said David Throup, a senior Africa Program associate with the Center for Strategic & International Studies. “He could not afford to lose.”

This isn’t the first time Akufo-Addo has contested the presidency; in 2008, he ran and narrowly lost to the NDC candidate John Atta-Mills. Violent protests erupted on the streets of Accra in support of the NPP, but they were short-lived, and the opposition didn’t take long to accept the electoral results. (Atta-Mills passed away unexpectedly in July, leaving Vice President Mahama to take up his mantle.)

Things are different this time around because NPP officials know that whichever party dominates the government over the next few years will benefit from incoming oil revenues, which could deliver a long-term, legacy-building boost.

Massive reserves of crude were discovered in Ghanaian territory in 2007, and the first drops of oil began to flow from an offshore rig in December 2010. Oil revenues in 2011 amounted to $444 million, but only $167 million of that went to fund the national budget. In total, the profits contributed only about 1 percent of the national GDP that year, which has not been enough to make a major difference for the majority of the Ghanaian population.

Fortunately, for roughly one-fourth of Ghanaians who live in poverty, things are expected to change as years pass. Peak oil production should be reached by 2015, and it will be up to the government to make sure those long-awaited funds are put to good use.

“It was clear that whoever won in 2012 would be extremely well-placed to dominate the Ghanaian political scene, not simply for the next four to eight years but probably for the next two decades,” said Throup. “This was a make-or-break election, and the NPP has pulled out all the stops to win.”

During the campaign, the NPP stirred up ethnic divisions to increase turnout among historically supportive communities.

The ploy didn’t work, partly because Ghanaians are generally wary of divisive tactics. A common phrase on the streets of Accra is “Ghana in peace, not pieces.”

The population of 25 million has good reason to guard the country’s reputation for stability. Decades of healthy democracy have ushered in an era of unprecedented growth; in 2011, the economy grew by 14.4 percent, giving Ghana middle-income status -- a major point of pride.

The NPP’s refusal to accept Mahama’s victory casts a shadow over the recent vote, but this isn’t the first time the party has reacted bitterly to defeat. The NPP lost a presidential election in 1992 by a wide margin, and responded by boycotting parliamentary elections two months later. It thereby lacked any parliamentary representation for the next four years, and it was a full eight years before they resumed their old position of power, enabling the NPP’s John Kufuor to win the presidency in 2000.

Then as now, the NPP may very well be shooting itself in the foot by refusing to recognize the NDC’s victory. Ghanaian support is now Mahama’s to lose.

“I don’t think most Ghanaians want to tarnish their country’s reputation as one of Africa’s best democracies,” said Throup.  “If the NDC doesn’t mess it up, this is a trend-setting election ushering in a whole new era for Ghanaian politics.”