Clinton's aggressive attempt at persuasion didn't work in Richardson's case, but that hasn't stopped her campaign from honing its pitch to the party leaders who could decide the nomination.
Clinton adviser Harold Ickes recently admitted to bringing up the Reverend Wright controversy in his conversations with superdelegates, in order to try to convince them that Obama's baggage may be too heavy to beat John McCain.
Of course, the Obama campaign isn't just sitting on its heals while the Clinton operation tries to wrangle as many superdelegates as possible, and party leaders are being solicited actively by his campaign, as well. Al Gore even joked that he was getting so many call from both sides that in order to do his "60 Minutes" interview with Leslie Stahl, he had to disconnect his phones.
But Obama's frontrunner status affords him the luxury of taking a more nuanced approach to wooing superdelegates. The Illinois senator does not have to take the kinds of risks that Clinton does in trying to convince party leaders that his opponent is fatally flawed.
Obama has recently been described as more "magnanimous" in his approach to Clinton, an approach that the Obama campaign seems to hope will signal to superdelegates that when he becomes the nominee, the wounds of the party will heal rather quickly. The Clinton campaign, on the other hand, may not be able to attempt such subtleties.