A former chemistry professor and provincial governor hand-picked by President Olusegun Obasanjo won the presidential election in a landslide Monday, in a vote denounced as deeply flawed by international observers and the opposition. Umaru Yar’Adua must now fight for credibility in Nigeria, where some 15,000 people have died since strict military rule ended in 1999. Gen. Muhammadu Buhari, the 1980s-era military leader who was the runner-up in Saturday’s vote, called the outcome “the most blatantly rigged election results ever produced in Nigeria.” Full Story