Does Gore Matter?

Marc Ambinder asks the DC question du jour, namely now that he's got a nobel prize, who's Al Gore going to endorse in the Democratic primary:
Two candidates -- John Edwards and Barack Obama -- are working the ref. Gore has met privately with both men, and the two were the first to e-mail congratulatory statements upon the news of Gore's Nobel dropping. (Edwards's campaign hit the trigger at 5:17 a.m.)
Perhaps the bigger question, though, is how much would it really matter. John Edwards' campaign is, at this point, severely hampered by financial constraints and by a perception that he's already lost. Gore can't help Edwards on the former item, since he's already accepted public financing, and I'm not sure his say-so would convince anyone on the latter point. Because unions are well known for not wanting to endorse candidates they feel are doomed, more union endorsements would have been very helpful to Edwards because they would have both helped him directly and bolstered perceptions that he's in the game. I don't think Gore can do that.
Obama has a different problem, namely that a majority of Democrats -- and especially the more economically and educationally downscale ones -- think Hillary Clinton's pretty awesome. Gore saying Obama's awesome, too, isn't really going to change things. Now what really might change things would be if Gore were to endorse Obama and use his standing as a former Clinton administration insider to mount a serious indictment of Hillary's key credential -- her experience in that office. But that assumes that there's some reasonable indictment to make of her tenure as First Lady that we haven't already heard and that Gore would be interested in doing something like that. Neither of those strike me as especially plausible, so under the circumstances I'm hard-pressed to see what kind of difference a Gore endorsement would make.