11.   But Orlando Paredes, the PRI candidate, has vowed to challenge the results in court in what some political observers view as an act of desperation.

12.   But their result was immediately challenged by another biologist.

13.   But these results were soon challenged by George Borjas, a Cuban-born economist now at the University of California at San Diego.

14.   Coalition candidates are also challenging the results of the recent election.

15.   Delta spokesman John Kennedy said he was unaware of any plans to challenge the result.

16.   Dornan says voter fraud denied him victory, and he is challenging the results.

17.   Despite widespread reports of voter fraud in Illinois, Nixon decided not to challenge the results.

18.   Even on Sunday evening, when preliminary results were already showing that Labastida had won by a landslide, Madrazo appeared to be preparing to challenge the results.

19.   Fox, a rancher who governed northern Guanajuato state, has said he would challenge the results if PRI wins by a narrow margin.

20.   He also suggested that he would not challenge the results of the Electoral College.