Group of persons organized to acquire and exercise political power.
Formal political parties originated in their modern form in Europe and the U.S. in the 19th century. Whereas mass-based parties appeal for support to the whole electorate, cadre parties aim at attracting only an active elite; most parties have features of both types. All parties develop a political program that defines their ideology and sets out the agenda they would pursue should they win elective office or gain power through extraparliamentary means. Most countries have single-party, two-party, or multiparty systems (see party system ). In the U.S., party candidates are usually selected through primary election s at the state level.