Originally posted by Turnbull:
Right there, I think he's saying, "If senators and governors can lie, cheat, take money from the treasury, and order the use of force to put down strikes, fight wars, etc.--and be considered legitimate--why shouldn't I be considered legitimate?" It never seemed to have occurred to him that the political pezzanovanti were using the law to legitimize themselves, whereas he was flouting the law.
Turnbull you are exactly right, but there is another interesting twist to all of this. At the end of GF I Michael tells his father that if he had become "Senator Corleone, Governor Corleone," he would just be another pezzanovanti. By the time of GFIII, it is Michael's wish to actually be a member of the pezzanovanti by going "legitimate" with the Immobiliare deal and by getting the recognition he got from the Church. Of course he is foiled because the Eurpoean pezzanovanti do not want him to take over their company (and they deftly use Altobello and Zasa to thwart Michael in the US).
Michael's reaction to all this is revealed the evening of the day he made his confession to the Cardinal, when he tells Connie he has spent his entire life trying to rise up in the legitimate world, but "the higher I go the crookeder it gets." He echoes this sentiment on the day he and Dontomassino and the others hatch the plan in the Garden for Michael to visit the Cardinal. It is there when he says that the "real Mafia" are the rich European business cartels like the one he is opposing.
In other words Michael is constantly deluding himself into believing that he is somehow more worthy of legitimacy than others are, and that whatever actions he takes against his "enemies" are thus justified.