Abubakar' first and most senior wife Hajia Titi Abubakar, is believed to be an Ilesha-born Roman Catholic, hailing originally from the Togolese Republic; together they have four children and five grandchildren. He has three other wives: Rukayat (the daughter of the Lamido of Adamawa, an influential monarch whom her husband served as a ranking nobleman of his kingdom); Fatima, a lawyer based in Lagos (Kanuri From Borno State) and Jamila (Formerly Jennifer Iwenjiora, an Ibo woman from Onitsha, who was a former television newscaster and who attained her doctoral degree in the United States). As a result, political associates and critics tend to agree that Atiku is one of the most detribalized northern Muslim aristocrats. All together he has 27 children.
His Controversial Life

In August, 2005 Abubakar surfaced in a report by the BBC World Service, as the intended recipient of a bribe as part of a scheme involving United States Congressman Bill Jefferson to promote Nigeria's adoption of internet technology from the American firm iGate, Inc. According to the FBI, Jefferson allegedly told an informant that he would need to give Abubakar $500,000 "as a motivating factor" for business contracts, but there is no evidence that Abubakar received nor sought[citation needed] such a bribe, which makes some skeptics think that Atiku may be a target of a witch-hunt. Jefferson had allegedly collected $100,000 from a business partner to give to Atiku, but $90,000 of the marked money was later found in the Congressman's house wrapped in a foil and neatly tucked away in a freezer.In August 2009, the court clarified that the former vice-president did not receive any bribe from Bill Jefferson. Atiku said he had consistently maintained that he had no improper relation with Bill Jefferson. Mr. Atiku also insisted that "it is now clear that the plot was hatched at the highest level of the Nigerian government then, in collusion with foreign agencies. The plot was not just to stop me from running for the Presidency; it was aimed at denying the Nigerian people the right to choose their own leader". More comments Please.
http://en.wikipedia.org/wiki/Atiku_Abubakar

Atiku mistake was that he did not pick his vice president before the primary. That was not a smart idea.

If atiku had picked either Yoruba or igbo, the voting would have been different.