I think it's fantastic - as with all advice, take what you need, and ignore the rest! It's only opinion and you know where you're going with this better than anyone else. I love the concept and, IMO, think the coloured backgrounds reinforces that there are oposing opinions and just helps break it up. I wonder now how you're going to adapt it once you have hundreds of postings? Presumably you want to stimulate debate on the postings? So you're going to need to keep them easily accessible. I've given you a digg, and I'd also suggest you add RSS feeds (probably one for each party?) so that people can subscribe and see new postings as soon as they happen. Anyways, good luck with it. I think you've got a potential winner there.