I've seen good discussions in comment threads on various political-themed blogs for my local area. One that springs to mind is the Seattle Transit Blog. They

I've seen good discussions in comment threads on various political-themed blogs for my local area. One that springs to mind is the Seattle Transit Blog. They have a good (bad?) number of trolls. However, they don't tend to overwhelm the discussions about the history of regional transit policy and how it relates to municipality X's service imbalance.