After the Cold War, Coups and Pronunciamientos fell into disfavor, but new forms of irregular regime change occurred. For instance, Presidents De la Rúa in Argentina, Bucaram in Ecuador and Sánchez de Lozada in Bolivia were ousted from office through massive street protests confronting governments unwilling and/or unable to repress them.

But street protests and riots usually happened after ousted presidents took office, not before, as Mexico's López Obrador is trying to do. This might be the first case an attempted preemptive overthrow of a President in Latin America since the end of the Cold War. The closest comparison would be the Peruvian democratic opposition fierce street protests against the attempted second reelection of Alberto Fujimori in the year 2K. Fujimori managed to be sworn in, but had to quit in disgrace a few months later.

López Obrador's a priori attempt at forced regime change in Mexico will face the same problems that all more or less non-violent strategies of civil disobedience do. They are not sprints but rather medium and long distance affairs: Not anaerobic but aerobic revolutions. If a critical mass of people is willing and able to sustain that rather challenging and uncomfortable state of daily, non-violent subversion, and if they face an over-repressive or weak government, they might succeed. But to keep huge masses of people angry and motivated for a long period of time is not easy, especially when sizable sectors of society have a lot to lose if the caudillo has his way.

I think that López Obrador has a chance if he succeeds in provoking President-elect Calderón into rash, panicked or simply stupid actions. Otherwise, Obrador will probably suffer a gradual erosion in his support leading all the way from him being an alternative to becoming a nuisance. He's stubborn but not dumb and probably realizes that the key to his success or failure lies not anymore in what he might do, but in Calderon's initiative, or lack of it.