Star Wars episode three, or Sith=Republicans

so yeah, I just got back from seeing episode three. It was much better than the last two, but I still felt like it was lacking something. Not sure I can put my finger on what exactly. At least they tied up some loose ends. I kinda felt like the politics was just a tad heavy-handed. I mean, Anakin says "If you're not with me, you're my enemy", and Obi-Wan responds "Only a Sith deals in absolutes". I felt this was obvious commentary on the current situation here in the US, what with a leader who takes absolute control under the guise of wartime neccessity. But that's just me being a dirty liberal, I guess. Otherwise, a good film, all things said. I am left with one question, though: just who is uncle Owen? I mean, Luke's uncle, obviously, but on which side? How is he related to Anakin? I know the answer's in episode IV somewhere, I just can't remember it. He's Anakin's brother, right? So why have we never heard of him before this? (or have we?) And wasn't Anakin an immaculate conception according to his mother in episode one? What's up with that (apart from the Jesus analogy)? okay, so that's a lot of questions, but they're all related.

Additional thought: It also seemed like love made Anakin become evil. I found this interesting.