Read the following passage: personally, i think a lot of people won't support third-party candidates because they might not be effective. if a third-party candidate gets into office, he or she will have a hard time accomplishing anything, since members of the two major parties vote together and control most things. which factor supporting the two-party system does the passage describe?

 the correct factor is majority rule

 the principle of majority rule is a fundamental aspect of democracy. in a democracy, it is the majority that rules and not the minority. This is the principle that has brought about the  need for coalition governments and two party systems in several countries especially the USA. A third party candidate in a two party system can not rule effectively because he needs a majority to do this.