In Star Wars: The Clone Wars (TV),
Ahsoka Tano is excommunicated from the Jedi Order.
In the show we see Anakin fighting against this conviction, believing in his padawan when nobody else will.
My question is:
Was the excommunication of Ahsoka Tano one of the main reasons for Anakin's conversion to the Dark Side via him losing faith in the righteousness of the Jedi Order?
I do not believe that it was a main reason, but it was probably just another point he could use to justify his rebellion in the Jedi code. Especially when he was fighting so desperately with his feelings for Padme, and his alignment with the Jedi order.
I also believe that his turn to the Dark Side began very early in Episode II. This quote in a conversation between him and Padme:
It’s worse. He’s overly critical. He never listens. He– He doesn’t understand. It’s not fair!
Anakin was responding to Padme acknowledging he'd grown up alot, and how lucky he was to have a master as fair and knowledgeable as Obi Wan. It's clear that Anakin drew some resentment towards Obi Wan quite early, and was frustrated with him, and felt he was holding him back.
Lets not forget that that Episode II is set 10 years after the events of Episode I, and the relationship between Palpatine and Anakin is made clear, Palpatine had already been influencing Anakin from a distance for years by this point. It wouldn't be too far-fetched to say that his dark side influence and clouding of judgement would be effecting Anakin's ability to see that Obi Wan was trying to be wise, not letting Anakin jump ahead of his station too quickly.
The plot is much simpler than thought. Palpatine wanted Anakin as his apprentice, and as such he secretly used his influence in the dark side to make this happen in every facet of the young man's life, including his romantic relationship with Padme, and relationship with Obi Wan. The entirety of Episode II was a vessel to show the beginning of Anakin's fall, even if to the simple eye, he is still a strong follower of the Jedi code of practice.
While the situation with Ahsoka certainly did impact him in ways that may have been a factor in his decision to betray the Jedi, the actual turn itself really boiled down to a single moment: his choice to save Palpatine, and for sole purpose of saving Padmé.
One of the primary plot elements of "Star Wars: Episode III" is the reason why Anakin makes the turn to become Darth Vader, which from a story perspective means that the viewer needs all the information necessary to understand and accept that choice. All throughout the movie, we witness his frequent dreams of Padmé dying and the fear that it brings him. The Jedi give him answers he doesn't want to hear, and when confiding in Palpatine, the chancellor reveals that there may be a way to save his wife (and in doing so admits that he is a Sith lord).
Anakin, still bound by his loyalty to the Jedi, decides to warn the council. What he assumed would be an arrest ends up turning into a fight that leaves only Mace and Palpatine standing, with Anakin on the sidelines as the deciding factor. Palpatine uses this opportunity to specifically focus on and take advantage Anakin's fear of losing Padmé, and it is for this reason that he makes his choice.
Could the way the Jedi council treated Ahsoka have been something he considered as a reason for turning on them? Probably, just as we can certainly say that his own feelings of betrayal by the council (for not granting him the title of Jedi Master) were all considered. All of this on top of the situation at hand, with Palpatine "calling for mercy" and Mace not having any of it.
But all of these were mere ripples to the wave of fear that was the loss of Padmé. While he does claim that "It is not the Jedi way", this was more likely his trying to justify keeping Palpatine alive (the last thing Anakin says before doing the deed was "I need him"). It was for that reason that he chose the path to the dark side, to follow Palpatine and learn from him of how she might be saved (as he says afterwards: "I will do whatever you ask...just help me save Padmé's life. I can't live without her.").
Here's the clip of his choice and subsequent turn:
No It was not at all the Main reason in fact it was probably a pretty small reason. Anakin's fall to that Dark Side started years before when he saw his Mother Die right in front him and he slaughtered a whole village of Sand People and was Complete when he learned of Padme's death everything in between was gradual with reason after reason to turn stacking up until he came to the tipping point.
