Demonstrators rioted on Friday after Senegal’s Constitutional Council approved incumbent President Abdoulaye Wade's effort to run for a third term in upcoming elections . . . the court upheld its ruling late Sunday . . . the opposition has vowed to make Senegal "ungovernable" if Wade wins the February 26 elections . . . one police officer died during the protests . . . term limits were established in 2001, a year after Wade was first elected . . . the U.S. State Department urged Wade to step down on Friday . . . Senegal is likely to see significant unrest as the election approaches . . . the fragmented opposition makes it possible that Wade could win re-election, especially if he can take advantage of his supporters in rural areas.