that he doesn't want to work for someone else, to offer his talents and judgment up to potentially be ignored.  That's very much the subtext of what he has to say about the Clinton administration & Kyoto, IMO... he's not necessarily bitter about it, but he also knows that he wasn't really in a position at the time to do any real arm-twisting or to make a big deal out of it.  That's just how it is when you're not the boss, lol, and Gore doesn't have to be a subordinate any more, even as a highly-placed counselor.  He's sort of the anti-Cheney in that respect-- not to mention in many others, of course.