Nobody says Atiku is not a Nigerian now. The cogent point about his eligibility to contest to be president of Nigeria is that he was not born a Nigerian. i.e.He wasn’t Nigerian at birth as required by the Constitution! He became a Nigerian in 1961 after a referendum added his birthplace that was part of Cameroon to Nigeria at age 15, having been born in 1946.
The constitution is very clear on who can be president of Nigeria. The person has to be 100% a Nigerian at birth.
You cannot backdate the referendum of 1961 that made Atiku become a Nigerian to the date of his birth in 1946. However, all Nigerians born in that his birthplace since 1961 referendum are fully and wholly Nigerians who are qualified to be president of Nigeria, but not anyone of them born before the referendum.
Summarily; Atiku Abubakar is fully a Nigerian but not qualified to be president of the country.
His case is similar to what the Republicans wanted to use to nullify Obama’s presidency, until he provided his birth certificate that showed he was born in Hawaii, on US soil. Unfortunately, Atiku wasn’t born on Nigerian soil as at the day he was born.
