Conservative and Liberal parties. The Radical party and later the Christian Democrats occupied the Center; the Socialist and Communist parties dominated the Left. This party system reflected the cleavages of Chile's rapidly changing socioeconomic system. Urbanization and the expansion of mining had generated middle-class and labor groups that demanded inclusion in the policy process. They chafed at the rigid socioeconomic system that reserved so much privilege and opportunity for only the elite. In this context, the Right mostly represented the interests of socioeconomic elites (the upper and upper-middle classes), although social Conservatives of the middle and even working classes, usually staunch Catholics, also gravitated toward the Right. For the most part, the middle and lower-middle classes supported Centrist parties, although anticlerical forces from the upper class also swelled the ranks of the Radical party, and some sectors of organized labor later backed the Christian Democrats. Usually, however, urban labor and much of the lower middle class sustained the Socialist and the Communist parties. Meanwhile, because of the social institution of the incjuilinaje, rural labor remained a captive voting block for Conservatives.
Each pole of this party system advocated different policies to promote economic development and social peace. The Right supported maintaining a good business climate, one that favored investment opportunities over redistribution of some of the national wealth to less advantaged social groups. By and large. Conservatives also opposed labor rights. The Center was more reformist. Centrists proposed greater state involvement in the economy to promote industrialization through public ownership, planning, and regulation, and they sought land reform to modernize agriculture. Centrists also championed social reforms in education, health, and housing and pledged support for organized labor. The Left advanced the same causes; the difference was in their ideological and programmatic emphasis. Influenced by Marxism, Leftists unabashedly pronounced that private property—its concentration in the hands of a few—was the root of social and economic inequality in Chile. Therefore, state involvement in the economy should be greater than that advocated by more middle class-oriented Centrist parties, and more radical land reform was required. Revolutionaries called for the abolition of most or all private businesses. Leftists believed in strong support for organized labor (higher wages, benefits, and rights) and generous fiscal expenditures for social reforms.
One of the keys to political stability in a polarized, multiparty political system in which each pole musters roughly a third of the votes lay in the flexibility of the Centrist parties. Since they frequently won the highest plurality, they had to be willing to enter into governing coalitions with either the moderate Right or Left, depending on circumstance. This ensured policy moderation and majorities in the congress with which to pass legislation. Knowing that they might become part of governing coalitions also kept the Right and Left poles of the system from radicalizing and, thus, from destabilizing the system. However, because presidents could only win by pluralities, when parties of the Right and Left won, they too had to be flexible and enter into governing coalitions with centrist parties.