Proportionality in the U.S. and Latin America

My paper will discuss some of the historical institutional features, including especially the presence vel non of stable, centrist political parties, mediating legislative and administrative institutions, and the subject matter jurisdiction of apex courts, that have made the United States and Latin America differentially fertile ground for proportionality-style reasoning. I will also discuss how more recent evolution in these features might bear upon particular jurisdictions' current fit with proportionality.