Boisterous crowds packed the streets for the retired general, while young men climbed lampposts, walls and billboards to glimpse his gaunt face. Others danced on careening motorcycles, brandishing homemade brooms, symbols of his campaign. With Nigeria ’s presidential election only weeks away, Boko Haram’s unchecked rampaging here in the country’s north is helping to propel the 72-year-old general, Muhammadu Buhari, to the forefront. After ruling Nigeria with an iron hand 30 years ago as the country’s military leader, Mr. Buhari is now a serious threat at the ballot box, analysts say, in large part because of Boko Haram’s blood-soaked successes. “The state is collapsing and everybody is frightened,” Jibrin Ibrahim, a political scientist with the Center for Democracy and Development in Abuja, the Nigerian capital, said of Boko Haram. “They are able to capture more and more territory, but also increase the level of atrocity,” he […]