Felipe Calderón damaged his honor when he campaigned on the notion that his opponent was a danger for Mexico. AMLO, for his part, destroyed his democratic credentials when he said to hell with the institutions. That ordeal between these two figures seems very distant today, but it still serves to explain why a good part of the Mexican society lost confidence in the alternatives to the PRI.There's probably some truth to AMLO and Calderón's role, but I don't think he gives Peña Nieto enough credit in this version. Clearly the PRI and Peña Nieto are in better shape thanks to the blundering by the opposing parties--politics is zero-sum like that. But he's far more a phenomenon of his own than he is a reaction to AMLO and Calderón. There's no way to know for sure, but I sure think the 2012 version of Peña Nieto would be the favorite in a three way race with AMLO and Calderón. And the hypothesis that Calderón so turned people off from the PAN with the "danger for Mexico" spot is at least somewhat undercut by the fact that Calderón won the presidency a couple of months later.
Raphael also writes:
It was 2006 that the PAN and PRD demonstrated that they could be as voracious and irresponsible as the worst PRI governments.Again with this? They most certainly did not show that. For the PAN and the PRD to be as bad as the worst PRI governments, they'd need to send the army to massacre hundreds of demonstrating students, engineer a handful of homemade financial crises, steal elections as a matter of course, and have the president's brother use his influence to, ahem, squirrel away several hundred million dollars, among other niceties. There's no comparison. The PAN governments haven't been fantastic, and a PRD government under AMLO would in my mind surely be worse, but there is an ocean of distance between either of them and the PRI of Echeverría and Díaz Ordaz.