Brad DeLong has made a stab at how to classify conservatives by their degree of honesty. The discussion at his blog refines it some (and some commenters think conservatism has always been just a con), but here’s the first take:

“Class of 2000: People who in 2000 said, ‘George W. Bush is not qualified to be president, and we should be really worried about this.’

“Class of 2001: People who in 2001 said, ‘I supported Bush in 2000, but George W. Bush is not listening to his honest conservative policy advisers, and we should be really worried about this.’ John DiIulio

“Class of 2002: People who in 2002 said, ‘I supported Bush in 2000 and 2001, but 911 has unhinged the administration; it’s detention and other policies are counterproductive; it needs to be opposed.’ Richard Clarke

“Class of 2003: People who in 2003 said, ‘I supported Bush over 2000-2002, but enough is enough. That’s it. I supported the invasion of Iraq because I was certain there was evidence of an advanced nuclear weapons program–otherwise invading Iraq was just stupid. Well, there was no advanced nuclear weapons program. Invading Iraq was just stupid. Plus there’s the Medicare drug benefit. These people need to be evicted from power.’ Tim Barnett, Bill Niskanen

“Class of 2004: People who in 2004 said, ‘I’ve been a Bush supporter. I’m a Republican and a conservative, but I’ve had enough: I’m voting for Kerry.’ Andrew Sullivan, Bruce Bartlett, Brent Scowcroft

“Class of 2005: People who in 2005 said, ‘I voted for Bush in 2004. But I made a mistake. A big mistake.’

“Class of 2006: People who in 2006 said, ‘I know I supported Bush up to last year, but that shows I’m not the brightest light on the clued-in tree.’ Rod Dreher, Andrew Samwick

“The class of 2007–people who are now opposed to Bush only because they think Bush will drag the Republicans down in 2008–doesn’t count.”

This seems like a good idea to me. The point is to acknowledge that there’s a stream of thought that isn’t liberal that has many good points and is worth debating with — and to distinguish legitimate heirs to that stream from worshippers at the golden calf that is W. But however — DeLong lifts a perceptive comment by John Emerson that calls into question the whole project.

A similar stratification of conservatives by the time of their acknowledgment that human-caused climate change really is a catastrophe in the making would be useful.