The new Pew Poll on public knowledge of current affairs includes the sadly routine finding that Fox News is doing a remarkable amount of nothing for its viewing audience. Subjected to 35 questions about the news, regular viewers of Fox scored directly in the national average, showing no sign of enhanced knowledge for all the time spent before Brit Hume. Blogs, too, appeared to do little good for their audience, lifting scores by only 2%. The Daily Show and Colbert Report either attract or educated the most informed viewers, along with newspaper websites, PBS, NPR, Limbaugh, and O'Reilly. Maybe none of this should be surprising, though. In the end, Fox News doesn't exist to inform -- it exists to convince. And in that, it's doing just fine.