Complex sentence: Obasanjo was re-elected in a tumultuous 2003 election that had violent ethnic and religious overtones, his main opponent, fellow former military ruler General Muhammadu Buhari being a Muslim, who drew his support mainly from the north.
Split into simpler sentences: Obasanjo was re-elected in a tumultuous 2003 election that had violent ethnic and religious overtones. His main opponent, fellow former military ruler General Muhammadu Buhari, was Muslim and drew his support mainly from the north.