Senegal's opposition presidential candidate Macky Sall (C) speaks on February 29, 2012 in Dakar during a press conference. Macky Sall on Wednesday strove to unite the opposition behind him for a March 18 presidential run-off after emerging as the challenger to President Abdoulaye Wade in the first round. Intense political wrangling got under way as the opposition urged its voters to rally around Sall and thwart the veteran leader's efforts to secure a third mandate and rule into his 90s. AFP PHOTO/ ISSOUF SANOGO (Photo credit should read ISSOUF SANOGO/AFP/Getty Images)