The Jedi figured it out when Sidious revealed himself, but did Padme, Bail and Mothma know it? If they do, they could try to collect evidence against him.
I think it's a bit simplistic to simply say Sidious was behind the CIS. It seems to imply belief it wouldn't exist but for him, which I don't agree with. Did they know for certain, I doubt it. Suspect it, likely.
Nah, they just thought he was at worst power-hungry and opportunistically using the war to his own advantage. If they had tried to collect or present evidence against him, I imagine they would have met their ends quickly in unfortunate accidents.
Obi Wan told Padme that Palpatine was the Sith lord they've been looking for and was behind the war. I would like to think that Yoda and Obi Wan told Bail, and then he would eventually tell Mothma since they were some of the founders of the rebellion. Collecting evidence would be helpful, but I doubt it would have made much difference after he declared himself emperor and declared the Jedi traitors to be hunted down. They would most likely get killed in some unfortuate accidents.
I think Bail knew after Palpaltine turned the Republic into the Empire. Im curious what was Palpatine's, Tarkin n Bails relationships like after ROTS n before ANH. Tarkin seemed to have no issue blasting Bail n his planet to bits. Its almost as if he enjoyed it. Im also curious how many separatists joined the rebellion after some time too. Their may have been planets or systems that just didnt agree with Palpatine when he was Chancellor n hated him more as an Emperor.
Padme knew, Obi-Wan tells her before he goes to fight Anakin, Bail Organa almost certainly knew, it's kind of implied since he was Yoda's backup during the assassination attempt on Sidious. I don't know how much evidence they would be able to come up with, or if it would help at all at that point.
The existence of Sidious as the mastermind behind the CIS was a secret known only to the jedi order and higher ups in the CIS itself. To most people, senators included, there was no Darth Sidious. That's how Palpatine was able to convince the public that the jedi order was Dooku's puppet master.
TCW: Wild Space portrays Bail as being very shocked when Padme reveals to him that "the Sith are real."
Padme knew after Obi-Wan told her. I feel quite certain that Yoda and Obi-Wan would've discussed it with Bail, too. In the Senate, when Padme tells Bail that the Chancellor has been elaborating on a plot by the Jedi to overthrow the Senate, Bail gives Palpatine a telling look. I think he knows the Jedi plot is not true. He probably figures out the rest shortly thereafter. Unless Bail told her anything, then Mon Mothma probably doesn't know. At least not until the years leading up to the OT.
Indeed. That's why the scene with Obi-wan and Padme was billed as the scene that explains it all, way back in 2003-04.
It had nothing to do with Bail personally. Tarkin wanted to make an effective demonstration of the Death Star's power, both to Leia and to the Republic at large as Alderaan is a core world.
