According to the Nouvel Observateur, Chirac could still possibly run for president:

A l'idée que Jacques Chirac pourrait siéger au Conseil constitutionnel - avec Giscard! - la voilà remontée à nouveau. "Oui, il ira. Dans cinq ans !" Et elle répète: "Vous m'entendez. Dans cinq ans"... On ne saurait être plus clair.

At the idea that Jacques Chirac could take his place at the Constitutional Council [as a former president] -- with Giscard [d'Estaing]! --  [his wife, Bernadette] braces up again.  "Sure he will.  In five years!"  And she repeats: "You hear me?  In five years."... One couldn't be more clear.

Seriously?  Does septuagenarian Chirac despise Sarkozy so much that he would go through the trouble of running for president (with no chances of winning, I gather) just to sabotage Sarkozy's chances?

Truth unfolds in time through a communal process.