 In 1991 all elections in Louisiana—with the exception of U.S. presidential elections—followed a variation of the open primary system called the jungle primary.Candidates of any and all parties are listed on one ballot; voters need not limit themselves to the candidates of one party.Unless one candidate takes 50% or more of the vote in the first round, a run-off election is then held between the top two candidates, who may in fact be members of the same party.