political party, organization whose aim is to gain control of the government apparatus, usually through the election of its candidates to public office. Political parties take many forms, but their main functions are similar: to supply personnel for government positions; to organize these personnel around the formation and implementation of public policy; and to serve in a mediating role between individuals and their government. Political parties are as old as organized political systems. For example, many of the ancient Greek city-states had organized, competitive parties. Political parties have been organized for various reasons: to support a particular political figure, to advance a particular policy or a general ideological stand, to aid politically certain groups or sections of society, or merely to combine for short-term political advantage. Political parties have also been organized in various ways; in some, control is exercised by a small central elite, either elected or self-perpetuating, while in others, power is decentralized, with candidate picking and decision making spread among local party units. The modern mass political party has taken shape in the last century, along with the rise of democratic ideology, universal suffrage, nationalism, and more effective means of communication. Such a party is commonly categorized by the type of party system in which it operates. In a noncompetitive or one-party system, the party is often employed as part of the governing apparatus, with the functions of maintaining public support for the regime, encouraging popular participation in government programs, and alerting the government to changes in public opinion. In competitive systems, a distinction may be made between two-party systems, which seem to encourage a party strategy of moderation and compromise aimed at obtaining a majority vote, and multiparty systems, where there is less compromise and where a party's strategy emphasizes retaining the support of its core voters. In general, however, the structure and behavior of a particular country's political parties depends most heavily on the country's political and cultural history.
See V. O. Key, Politics, Parties and Pressure Groups (5th ed. 1964); S. M. Lipset and S. Rokkan, ed., Party Systems and Voter Alignments (1967); R. S. Katz, A Theory of Parties and Electoral Systems (1981); R. L. McCormick, ed., Political Parties and the Modern State (1984); K. Von Beyme, Political Parties in Western Democracies (1985).