One of the things you bpick up around the blogosphere is the huge wads of self importance. I'm as guilty of it as anyone else - I've given whole talks on how crucial it is to pay attention to blogs. Having said that, there's another side of this, and it impacts tech bloggers and political bloggers alike - the "echo chamber" problem.
It's very easy, watching Technorati, and Memeorandum, and IceRocket, and Google's blog search, to get caught up in any of a number of ongoing conversations. Take a look at Scoble's latest comparison post, for instance. You see this kind of tail chasing all across the blogosphere, although it seems positively endemic on the political sites - I guess the egos are just that much bigger over there.
There's an easy reality check though, and I get it every time I visit customers. I ask "How many of you read my blog?" Now, as egotistical as that sounds, stay with me a second - in these meetings, I'm seeing Cincom Smalltalk customers, and a goodly proportion of what I (and the other bloggers here) cover is Cincom Smalltalk focused - so the cst blogs are pretty "on topic" for a customer crowd. The thing is, it's always a fraction of the audience that is reading.
Most people just aren't as focused on their jobs (or politics) as bloggers are. We tend to be obsessive about the topics we're interested in, posting multiple times a day. Most people don't spend even a fraction of that much time pondering the industry they work in or day to day politics. They have other things on their minds - family, sports, hobbies - other things that fill their time and make them happy. Meanwhile, bloggers - in any part of the sphere - will form a circle of self importance and blather about the huge impact they have.
Don't get me wrong - within an influential sector of the population, bloggers do have influence. It's just not as huge an influence as we would like to believe.