I don’t think anyone here is claiming that ROTS communicates all of it’s themes and ideas as well as it should have, the point is that they are there. Lore-wise the PT works quite well, but cinematically it fails on many points.
Exactly. The points are all there for people who watch the films repeatedly. It is not clearly done for the casual observer, though a lot might catch certain things and not question his turn. I think one of the biggest issues of the PT is that is really isn’t a prequel at all, it is a flashback. We already know Anakin becomes Vader so things aren’t setup very well if you follow the story chronologically. But the points are there. Palpatine maneuvers Anakin into an impossible position - save his friend and mentor who just might be able to help Padme or save a revered Jedi master who seems to be trying to take over the Republic. Which one is his duty to the Republic? Which one is the right choice? And as we see, he listens to Palpatine. He killed Dooku on Palpatine’s order. So when Palpatine has Anakin in that vulnerable state, he uses the dark side of the force to pull him the rest of the way over. He goes and slaughters the Jedi to preserve the Republic. It becomes the very thing he joked with Padme in ATOC. In point after subtle point, Lucas reinforced Anakin’s fall.
I caught all the points my first viewing. When I first saw it I was looking for the boxes to be checked off - ‘now he turns on Mace, now he kills the Jedi, now he fights Obi-wan.’ And they were checked! But the thing is that as I’ve gotten older and seen the films more that I realize how slapdash the sequence of events is. Lucas seemed to have the broad outline sketched out to begin with but never found a seamless way to piece it all together. To that end I sympathize with what some have said in this thread about ROTS being the worst of the PT - it does feel at times like slideshow storytelling.
And it seems clear that Palpatine is the one person Anakin trusts the most. So if Palpatine says something, Anakin will believe it. And he will believe it over the Jedi because of his long acquaintance and friendship with Palpatine. He probably has had more contact with Palpatine than any single Jedi. Palpatine made sure of that.
I don’t think that’s nearly as clear as you make it out to be (though again, I agree that’s what Lucas was going for). There’s literally no reason, based on what we see in the films, to think that Anakin would have had more contact with Palpatine than “any single Jedi,” when, in AOTC for example, they share exactly one very brief scene, whereas Anakin and Obi-wan spend almost half of the film together.
Either way, even if Anakin believes Palpatine over the Jedi, him believing Palpatine’s lie about the “plot” doesn’t make sense. Before that scene, we only have one other scene where Palpatine disparages the Jedi to Anakin, and he seems taken aback and defends them. Now sure, you could say that what Palpatine said there stuck with him, but still based on his reaction there (and lack of evidence to support the claim), one would think Anakin would be at least a little surprised that Palpatine says there’s a plot against him and the Senate. But no… he doesn’t just accept what Palpatine says as truth, he agrees with him, which suggests that Anakin must have come to that conclusion himself… but based on what? Sure you could say the dark side in that moment suddenly warped his mind, but even if that were the case, shouldn’t we have seen or heard something to suggest that? Him having a premonition or even just sensing betrayal or something? Nope, we just see Anakin being remorseful in one second about attacking Windu, and being a possessed slave to Palpatine’s orders the next.