The idea of a McCain-Lieberman centrist party seems to be spreading rather than dying. I think this makes about no sense whatsoever. For one thing, ex ante skepticism about any third party venture in the United States should always be extremely high. And there's nothing about the current situation that would make you think we're in line for an exception. To get a third party off the ground, you would neeed a new high-salience issue that cut across the existing political coalitions and we don't have that. While contemporary national security debates don't have a logical relationship to, say, the abortion debate it turns out to be the case that in practice cultural traditionalists and foreign policy hawks are overwhelmingly the same people.

Paying too much attention to the media tends to obscure this since people with unusual configurations of views tend to stand out from the pack. But demographically speaking, the sort of things likely to make you a dove are just the same things that make you likely to be a cultural progressive. The only substantial block of dovish cultural traditionalists, meanwhile, are African-Americans which tends to re-enforce rather than undermine existing coalitions.

But even this analysis may be giving the idea too much credit. What would a McLieberman Party be about? What would be centrist about it?

On national security issues, McLieberman would have a far-right profile -- both Lieberman and McCain have been occassional critics of the Bush administration's national security policies but those have almost invariably been complaints that it's been insufficiently hawkish.

On domestic issues, meanwhile, Lieberman is a pretty orthodox liberal and McCain a pretty orthodox conservative. Neither of them are great partisan foot-soldiers which does give them something important in common as dissident members of their respective legislative caucuses, but a shared taste for disloyalty isn't a very firm basis for forging an institutional partnership. What's more, McCain's major domestic unorthodoxies stem from his willingness to sometimes buck big business interests in pursuit of what he sees as a truer, realer conservatism. Lieberman, by contrast, votes with the Democrats on the "big issues" but has a proclivity for selling out to big business on low profile votes where he thinks he can get away with it.

If someone could show me some evidence that conservatives were prepared to accept Lieberman's domestic views (see counterevidence) that would be one thing, but nobody seems to have that. Conversely, McCain's liberal fans tend to make the case for their man by arguing that he secretly doesn't hold the views he says he holds. That may be the case but, again, he would need to actually change his views away from fairly standard-issue conservatism before any meeting of the minds could take place.