As usual with calls for less partisanship and more moderation, the striking thing about this new initiative is its vacuousness. There are two kinds of thing a centrist movement might reasonably stand for. One would be a middle-ground approach to issues -- "Democrats think federal revenues should be at X percent of GDP, Republicans think it should be at Y percent, but we say it should be at (X+Y)/2 percent of GDP." Another would be to hold a mish-mash of left-wing positions on some issues, and right-wing positions on others "we should reduce carbon emissions by 80 percent by 2050 through a 100 percent auction of tradable emissions permits and we should privatize Social Security." One might, of course, also have a combination of the two sorts of things.

So what do we hear?

Well, according to Stu Loesser, press secretary for Michael Bloomberg, "As mayor, he has seen far too often how hyperpartisanship in Washington has gotten in the way of making progress on a host of issues." Which issues? And what would constitute progress on them? Loesser doesn't say. Similarly, David Boren says that "Our hope is that the candidates will respond with their own specific ideas about how to pull the country together, not just aim at getting out their own polarized base." This, though, is just talk about political strategies. And if both countries put forward policies designed to appeal to the median voter, the result will be . . . polarization and election outcomes that hinge on the mobilization of one's base. Missing from Boren's account is any hint of what kinds of positions he thinks are being squeezed out in the current dynamic.

And there's the rub. There are only two political parties. Under the circumstances, polarization is all but inevitable. Third parties, meanwhile, never succeed in the United States but do often wind up having an impact on the course of events. But to have an impact, you have to have some kind of point of view that you're advancing. Big-time third party candidacies -- Strom Thurmond 1948, George Wallace 1968, Ross Perot 1992 -- aren't based on generic appeals to bringing the country together, they're based on policy agendas that neither major party reflects. You could imagine a third party campaign based on Ron Paul's brand of libertarian nationalism, but all Boren, Bloomberg, et. al. have are platitudes.