In this article, the authors compare the practices of discursive production among top U.S. political blogs on the left and right during summer 2008. An examination of the top 155 political blogs reveals significant cross-ideological variations along several dimensions. Notably, the authors find evidence of an association between ideological affiliation and the technologies, institutions, and practices of participation. Blogs on the left adopt different, and more participatory, technical platforms, comprise significantly fewer sole-authored sites, include user blogs, maintain more fluid boundaries between secondary and primary content, include longer narrative and discussion posts, and (among the top half of the blogs in the sample) more often use blogs as platforms for mobilization. The findings suggest that the attenuation of the news producer-consumer dichotomy is more pronounced on the left wing of the political blogosphere than on the right. The practices of the left are more consistent with the prediction that the networked public sphere offers new pathways for discursive participation by a wider array of individuals, whereas the practices of the right suggest that a small group of elites may retain more exclusive agenda-setting authority online. The cross-ideological divergence in the findings illustrates that the Internet can be adopted equally to undermine or to replicate the traditional distinction between the production and consumption of political information. The authors conclude that these findings have significant implications for the study of prosumption and for the mechanisms by which the networked public sphere may or may not alter democratic participation relative to the mass mediated public sphere.