Legalist vs. Interpretativist: The Supreme Court and the Democratic Transition in Mexico

Abstract

We examine the expansion of the policy making power of the Mexican Supreme Court since 1994, when a reform turned the court into a constitutional tribunal. We build on the intuition that the Court can never act against the interests of both the executive and legislative branches simultaneously, otherwise the ruling is likely to be overturned and/or justices sanctioned. The Court can only influence policy when the elected branches have polarized preferences and the Court itself is centrally located. Despite the onset of divided government since 1997, the conditions for Court influence only appeared with the triumph of the PAN in the presidency in 2000. Multivariate regression confirms that the probability of striking down a law increased significantly after that year, but only in rulings likelier to involve substantive ideological disputes. In rulings used to resolve federalism disputes the Court showed a marked propensity to side with the PRI, the party that set the new judicial system in place and also controls most subnational units. Justices also differ in their view of the Supreme Court's role in a democracy. We explore this by analyzing justices’ voting records to estimate their ideal points, revealing the existence of two dimensions. Case studies confirm that the first dimension of cleavage is the standard left-right divide of normal politics, and the second corresponds to legalism vs. interpretativism.

Keywords: Supreme Court, Judicial politics, Ideal points, Democratization, Mexico

JEL Classification: D70, K10, K40