A few points regarding the PRD's level of party institutionalization

Students of the Partido de la Revolución Democrática (PRD), Mexico's only serious leftwing party, tend to coincide on a few things: The party is not "institutionalized," in political science jargon, in that it has not a strong and firm party organization, it does not speak with one relatively common and consistent voice, it does not have clear established and respected internal rules for creating programs, recruiting candidates, and party leaders, and is in general involved in much internal and external turmoil. My main point has long been that the party cannot make up its mind whether to be a partido-moviemiento, or a movement-party of the personalistic kind, or a regular, more traditional party type, and to try to explain why this is so. A visual image might help here: To "storm" the congress dais and block the streets, or to work for gradual reform in congress.

Another clear indicator of whether a party has achieved or is moving toward institutionalization is the relationship it has with its party founder(s): Does the party continue to appear a mere appendage of the founder(s)'s ideas, program, or, to be sure, presidential candidacy? Or, has the party transcended its first leaders in that it does not merely follow his dictates, but has an autonomous program and leadership independent of him ? (thus far, invariably "him" and not "her").

I do not argue that the PRD today is an institutionalized party; its vicious infighting over the candidacy of AMLO vs. Ebrard, which the Mexico State 2011 election is but a mere proxy for, is a telling point here.
But: I do want to make note of one thing. Both Cuauhtémoc Cárdenas, the PRD's founder and 3-times presidential candidate, and Andrés Manuel Lópes Obrador, his hijo político and 2006 presidential candidate, are both rejecting the PRD-PAN alliance in Mexico State. However, the party leadership, under Jésus Ortega, is still following their own line. Ortega dixit: "One will keep in mind these opinions, but the strategy is to continue with the alliances."

In other words, whatever one thinks of the wisdom of the PAN-PRD alliances, I think it is an extremely healthy sign that the PRD is clearly demonstrating that it is no longer blindly following the dictates of AMLO or Cárdenas. I can think of no other PRD leader who has demonstrated a greater degree of autonomy than Jésus Ortega. While merely one step in a (very) long and larger process of party institutionalization, for the PRD's development this is nonetheless quite a leap forward.