I had a good talk with Griff Wigley of Northfield Citizens Online, a non-profit in Northfield, MN that promotes the "civic blogosphere" there. He provides leadership coaching to civic leaders who want to use weblogs effectively to communicate their voice and their ideas to citizens of their community.
NCO grew out of the Northfield Free-Net, and started 20+ years ago. Griff says that things really started to take off once they got connected to the Internet.
Here in Ann Arbor, there's not much engagement by local politicians to put their thoughts and ideas on civic life into blogs. (They are all on email, but media communications with the public is almost entirely via the local newspaper.) A notable exception is Larry Kestenbaum, the county clerk and register of deeds for Washtenaw County, who keeps a blog in which he often cc's the public on letters that he writes to his staff keeping them up to date on what's going on in his office. The civic blogosphere here is also well-represented by the Ann Arbor District Library which features a weblog by its director, Josie Parker.