As cognitive psychologist George Lakoff told me: "Democrats moving to the middle is a double disaster that alienates the party's progressive base while simultaneously sending a message to swing voters that the other side is where the good ideas are." It unconsciously locks in the notion that the other side's positions are worth moving toward, while your side's positions are the ones to move away from. Plus every time you move to the center, the right just moves further to the right.

And if middle-of-the-roadism is such a great vote-getter, why don't we see Republicans moving there? In fact, framing the political debate in right-left terms is so old, so tired, and so wrong that we need to resist all temptation to do so. There is nothing left-wing about wanting corporations to pay their fair share rather than hide their profits in PO boxes in Bermuda, or in ensuring access to health care now rather than paying the bill at the emergency room later.