There is good reason to believe that blogs are changing politics, but we don't know exactly how. Nor do we know whether the normative consequences of blogs for politics are likely to be good or bad. In this special issue, we and our co-authors undertake the first sustained effort to map the empirical and normative consequences of blogs for politics. We begin by setting out basic information about blogs, and some anecdotal evidence suggesting that they are indeed politically important. We go on to identify the key empirical and normative questions that blogs raise, and discuss the dearth of relevant data in the existing literature. We conclude by summarizing how the authors of the articles gathered in this special issue help fill this gap. © 2007 Springer Science+Business Media, BV.