A problem

Peope who don't understand why Anakin was, presumably, so easily induced by Senator/Emperor Palpatine/Darth Sidious aren't devoted Star Wars fans or don't understand the Force. "Don't under-estimate the power of the force" (said by the man himself). Anakin was not persuaded by a mere man, but by the Dark Side of the Force (a very powerful entity that can be harnessed as a tool by Jedis, good or bad). If you watch the movie again, you can see the Anakin is sometimes in a sort of trance when he's in Palpatine's presence. Yes, he did let his fears rule his life and influence his decisions (a path to the Dark Side, coincidentally) but the persuasive power of the Dark Side of the Force did have a large role in his conversion. Maybe the fact that he was, essentially, made by the Force (remember, he was created by medi-clorians) has something to do with it too.
I know, you're probably thinking "What about all he was taught and believed in, and what about his common sense..." and I'm sure the list goes on. Watch the movie again with a clear mind, neither expecting or presuming anything. If you still don't get it...I'm afraid I can't help you any further. Remember, this is George Lucas' work we're talking about here.

Let's just stick with the old movies, shall we (IV, V, VI)?