because they didnt want other poeple in there state im very sorry if the answer was wrong im desprate for points
The correct answer is: Voters have a wider choice of candidates and ideas.
In a bi party system there are only 2 options which in general have a very narrow ideology and therefore divide a country. As a voter you may not feel identified with any of them. When more parties participate, different ideologies are represented and those voters have a greater probability to find one that suits them. Also they have more chance that their ideas are represented in Congress.
Between France and England.( Britain)