A
two-party system is a system where two
major political parties dominate politics within a government. One of the two parties typically holds a majority in the legislature and is usually referred to as the
majority party while the other is the
minority party. The term has different senses. For example, in the
United States,
Jamaica, and
Malta, the sense of
two party system describes an arrangement in which all or nearly all elected officials belong to one of the only two major parties, and third parties rarely win any seats in the legislature. In such arrangements, two-party systems are thought to result from various factors like
winner takes all election rules. In such systems, while chances for
third party candidates winning election to major national office are remote, it is possible for groups within the larger parties, or in opposition to one or both of them, to exert influence on the two major parties. In contrast, in the
United Kingdom and in other parliamentary systems and elsewhere, the term
two-party system is sometimes used to indicate an arrangement in which two major parties dominate elections but in which there are viable third parties which do win seats in the legislature, and in which the two major parties exert proportionately greater influence than their percentage of votes would suggest.