Tres partidos políticos con representación minoritaria en la Cámara de Diputados (PRD, PT y Convergencia) amenazaron con impedir la toma de protesta del Presidente Electo Felipe Calderón el 1 de diciembre de 2006. Aquí se presentan dos artículos editoriales con interpretaciones distintas sobre las posibles consecuencias jurídicas del caso. Por un lado, Fernando Serrano Migallón, Director de la Facultad de Derecho de la UNAM, afirma que el Presidente Electo tiene que rendir protesta ante la Cámara de Diputados para asumir el cargo para el que fue electo. Por el otro, Diego Valadés, ex-Director del Instituto de Investigaciones Jurídicas de la UNAM, sostiene que el Presidente Electo asume funciones a la medianoche del día primero y que puede rendir protesta por escrito.

In 1969 Comparative Politics published a review article by William Riker entitled "Six Books in Search of a Subject or Does Federalism Exist and Does It Matter?." As the title suggests, the conclusions of the review were not very kind to the field of comparative federalism. Riker, in fact, questioned the very existence of federalism itself by stating that "federalism is no more than a constitutional legal fiction which can be given whatever content seems appropriate at the moment." When it came to whether or not federalism mattered, he was equally harsh. "Does federalism make any difference in the way people are governed? And the answer appears to be: Hardly any at all."

Riker's bleak verdict on the state of the literature reflected the divisions in federalism studies in 1969. More than thirty-five years later, the field of comparative federalism remains divided into separate pockets of scholarship. There are signs of revival in some of these subfields, but they seem to be going their own way without the benefit of a common framework that might encourage theoretical cross-fertilization. This review article aims to explore if there is indeed any common ground that could provide the basis for exchange and theoretical growth. But first, it is imperative to revisit Riker's provocative question. Does federalism exist, and does it matter?