Edwards is very much still in politics. Once a man gets the political bug, he's never really cured. But Edwards is almost certain to speak at the Denver convention, he is (or was) in the running-mate pool, and might be in consideration for any number of other positions (including a possible Supreme Court appointment) in an Obama administration. So his defenders can't be allowed to get away with the "he's just a private citizen now" gambit.
By the way, J.P., why were you reading that girls-only blog at Slate?