After a brief multinominal experimentation in 1882, proportional representation into large, regional, multi-seat electoral constituencies was introduced after World War I. Socialists became the major party, but they were unable to form a government in a parliament split into three different factions, with Christian populists and classical liberals. Elections took place in 1919, 1921 and 1924: in this last occasion, Mussolini abolished proportional representation, replacing it with the Acerbo Law, by which the party that won the largest share of the votes got two-thirds of the seats, which gave the Fascist Party an absolute majority of the Chamber seats.