Abuja - Its former national chairman once boasted that the Peoples Democratic Party (PDP) would rule Nigeria for 60 years. In the end it managed only 16.
Muhammadu Buhari's All Progressives Congress (APC) dumped the PDP out of power in presidential elections in March, in what was the first win for an opposition party in the country's history.
As attention shifted to Buhari and his plans to tackle endemic corruption and defeat Boko Haram Islamists, the PDP and its former president Goodluck Jonathan went quiet.
On Twitter, the main tool for the party's message in the election campaign, there were no more posts from the party from May 18, but on October 29 it announced: "We are Back!!!"
The PDP has been finding its voice again since then and on Thursday the party held a national conference in the capital Abuja to set out its plans to regain power.
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Buhari's crackdown on corruption has seen several former and serving state governors arrested on suspicion of corruption while he has accused the PDP of leaving the country virtually bankrupt.
Its language was typically bullish, describing the government as "the fascist APC regime" and accusing it of human rights and constitutional violations as well as abuse of power.
But the PDP declared: "Participants noted that the PDP remains the only credible national political institution committed to national interest and the deepening of democratic tenets and ideals."
Tub-thumping rhetoric and personal criticism has long characterised Nigerian politics, which relies heavily on patronage, elite connections and, very often, hard cash.
The PDP personally attacked Buhari during the election, accusing the former military ruler of being an Islamic extremist, an unreformed dictator and unqualified to hold office.
In the run-up to the vote, though, dozens of PDP lawmakers switched sides to the APC, complaining that Jonathan had reneged on a promise not to stand for a second term.
There have been more defections since then, in part due to PDP perceptions of an APC "witch-hunt" against its members over corruption.
Analysts attributed the PDP's election defeat to its failure to secure a consensus in a religiously and ethnically divided country and also that after 16 years, people were ready for a change.
Political commentator Chris Ngwodo said to build on the democratic development of the APC's historic win, what the country needed now was not rhetoric.
"Trickle-down politics of the worst kind", where powerful elites bestowed patronage on their supporters, was in the past, he said.
To become relevant again, the PDP "has to think more deeply" and come up with policies that address the lack of social and economic opportunities for Nigeria's young population across the country.
Simple criticism was "not moving anybody" he told AFP.
"There's no real sense of having an opposition party. This is a party shell-shocked from defeat, still grappling in the dark. It needs to define itself," he added.
"It's in Nigeria's interest for there to be an opposition party. We need that sense of competition, that keeps people on their toes."
Away from the formal debate, there were signs the message was being taken on board, as talk already turns to possible presidential candidates for 2019.
Former federal lawmaker Abdul Ningi agreed the PDP needed to get its house in order first and had "no business for now taking a critical look at this government".
"What is important, in my opinion, is taking a look at what we have done wrong and why Nigerians actually rejected us," he said on the sidelines of the conference.
"We have failed to inculcate democratic culture. We have ruled, on many occasions, with impunity...
"Nigerians have looked at us and realised we have derailed from our missions, dreams of the founding fathers."
Raymond Dokpesi, the conference's chief organiser, was criticised for apologising for PDP mistakes in a television interview last week.
"It is one thing to suffer such a set-back at the polls anywhere in the world," he said at the conference.
"But most significant and far-reaching is how quickly you learn from your mistakes and effect the requisite adjustment necessary to restore your winning ways."