Kevin Drum, writing in a blog for Washington Monthly in response to an argument from Juan Non-Volokh, enunciates what may become the new Democratic argument for the filibuster: you can't change the rules in mid-stream. He writes: "My broader point is that the real issue in the filibuster fight isn't the filibuster itself — or blue slips or Rule IV or any other specific rule — it's the general principle that rules shouldn't be cynically changed en masse just because your guy is in power and you've decided they're no longer convenient. As it happens, I'm not much of a...