Party Systems

A party system is a concept in comparative political science concerning the system of government by political parties in a democratic country. The idea is that political parties have basic similarities: they control the government, have a stable base of mass popular support, and create internal mechanisms for controlling funding, information and nominations.

The concept was originated by European scholars studying the United States, especially James Bryce and Moisey Ostrogorsky, and has been expanded to cover other democracies.Giovanni Sartori devised the most widely used classification method for party systems. He suggested that party systems should be classified by the number of relevant parties and the degree of fragmentation. Party systems can be distinguished by the effective number of parties.

Two structures of party system have been identified in the European Parliament since its first universal direct election in 1979, albeit the main EU party groups remained the same:

Italian party systems are usually considered only since the foundation of the Italian Republic (1946) as pre-fascist parties lacked a wide popular base.

The party system of the so-called First Republic (1946–1994), though based on a proportional electoral law, saw the dominance of the Christian Democracy (DC) and the conventio ad excludendum against the Italian Communist Party (PCI). DC and PCI together gathered around 85% of the votes in average. The system was thus a blocked bipolar system; governments were very short (in average lasting less than one year) and post-electoral, but the supporting parties and personnel could not change. With time, some parties (especially the Italian Socialist Party, PSI) gained momentum, till reaching the role of government-making in the 1980s. The system was completely destroyed by the bribery scandals of Tangentopoli, which shattered DC and PSI. According to Sartori, the two possible degenerations of proportionalism (fragmentation and lack of party discipline) were reduced by two factors: the strong role of parties ("partitocrazia") and the polarization between Christian-democrats and communists. Therefore, the first republic saw a maximum level of 5 effective parties, with only one dominant party.

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