Internal Unity and Ideological Orientation in Latin American Parties (1993–2020)

The internal unity of party organizations is an important aspect that impacts not only their dynamics but also their credibility in the eyes of the electorate. One commonly-used strategy for measuring this unity is to analyze the degree of intra-party agreement on policy issues. Despite this importance, there is a lack of up-to-date understanding of the internal unity of political parties in Latin America and of its determinants. In this article, we analyze the degree of agreement in the views of legislators’ ideological self-placement over the course of the last thirty years. Evidence suggests that this level of agreement is greater amongst members of left-wing parties than amongst their right-wing rivals. As has also been shown in Europe, in Latin America, the emphasis of these parties on ideology is a major influence on their dynamics, and the effects of this include more similar ideo­logical identities between their members.