In his blog today, Brad DeLong argued that TPC had been less influential over the past decade than the liberal Democratic think tank Center for American Progress. Brad's theory is that organizations such as TPC, the Brookings Institution’s Hamilton Project, and the Center for Budget & Policy Priorities have, essentially, been too wimpy to be effective. DeLong thus joins the camp of Paul Krugman (and Rush Limbaugh, Sarah Palin, and Newt Gingrich) in arguing that life in the middle-of-the-road makes you roadkill.