Party Systems

There are three types of party systems: (1) multiparty systems, (2) two-party systems, and (3) one-party systems. Multiparty systems are the most common party system. Parliamentary governments based on proportional representation often develop multiparty systems. In this type of government, the number of legislative seats held by any party depends on the proportion of votes they received in the most recent election. Advocates of multiparty systems believe they permit all points of view to be represented in government.

In a two-party system, government power shifts between two dominant parties. Two-party systems most frequently develop when an election requires a candidate to gain only a simple plurality vote—that is, the winner gets the most votes but not necessarily a majority. Advocates of two-party systems believe they limit the dangers of excessive fragmentation and government stalemate. Opponents believe that eventually the two parties tend to resemble each other and eliminate too many viewpoints from the political process.

In a single-party system one party nominates selected candidates, and there is no competition for elected offices. Voters simply vote "yes" or "no" for the designated candidate. Single-party systems have characterized Communist Party governments and other authoritarian regimes.