A one-party state, single-party state, one-party system, or single-party system is a type of unitary state in which only one political party has the right to form the government, usually based on the existing constitution. All other parties are either outlawed or allowed to take only a limited and controlled participation in elections. Sometimes the term de facto one-party state is used to describe a dominant-party system that, unlike the one-party state, allows (at least nominally) democratic multiparty elections, but the existing practices or balance of political power effectively prevent the opposition from winning power.
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2 Several states constitutionally deemed to be multiparty republics are broadly described by outsiders as authoritarian states. This map presents only the de jure form of government, and not the de facto degree of democracy.