<P> Though plurality (first - past - the post) is often mistaken for majority rule, they are not the same . Plurality makes the option with the most votes the winner, regardless of whether the fifty percent threshold is passed . This is equivalent to majority rule when there are only two alternatives . However, when there are more than two alternatives, it is possible for plurality to choose an alternative that has less than fifty percent of the votes cast in its favor . </P> <P> Although it is a binary decision rule, majority rule has become the dominant factor in many modern western democracies, with most elections and referendums being decided by majority rule . It is frequently used in legislatures and other bodies in which alternatives can be considered and amended in a process of deliberation until the final version of a proposal is adopted or rejected by majority rule . It is one of the basic rules prescribed in books like Robert's Rules of Order . The rules in such books and those rules adopted by groups may additionally prescribe the use of a supermajoritarian rule under certain circumstances, such as a two - thirds rule to close debate . </P> <P> According to May, majority rule is the only reasonable decision rule that is "fair", that is, that does not privilege voters by letting some votes count for more or privilege an alternative by requiring fewer votes for its passing . Stated more formally, majority rule is the only binary decision rule that has the following properties: </P> <Ul> <Li> Fairness: This can be further separated into two properties: <Ul> <Li> Anonymity: The decision rule treats each voter identically . When using majority rule, it makes no difference who casts a vote; indeed the voter's identity need not even be known . </Li> <Li> Neutrality: The decision rule treats each alternative equally . This is unlike supermajoritarian rules, which can allow an alternative that has received fewer votes to win . </Li> </Ul> </Li> <Li> Decisiveness: The decision rule selects a unique winner . </Li> <Li> Monotonicity: The decision rule would always, if a voter were to change a preference, select the alternative that the voter preferred, if that alternative would have won before the change in preference . Similarly, the decision rule would never, if a voter were to change a preference, select a candidate the voter did not prefer, if that alternative would not have won before the change in preference . </Li> </Ul>

Who decides whether a political party will be the majority or minority party