Let me second what Kevin Drum says here. I don't think you need to reach for far-out explanations to explain the continuation and ferocity of the Clinton Campaign. Rather, you just need an old political maxim: All campaigns look winnable to the people inside them. Just ask Bill Richardson, Chris Dodd, Joe Biden, and Dennis Kucinich. Ask Steve Forbes, Pat Robertson, Elizabeth Dole, and Dan Quayle. And Clinton's star power, and her lead in Pennsylvania, and the videos of Wright, and all the other disparate data points that exist in an election this large mean there's more than enough information for her to construct a plausible internal narrative explaining how she wins this thing. And for a candidate who's come so far and gotten so close, admitting defeat requires a pretty enormous psychological shift. Now, I think she's wrong. I think Obama's lead in pledged delegates and his lead in the popular vote effectively end her chances. I think that his implosion is unlikely, and if it happens, the delegates will be focused on placating his voters (particularly African-Americans), not fulfilling Clinton's hopes. And that might even lead them towards a third choice. But be that as it may, it's not hard to understand why Clinton thinks she can, and should, keep this fight going. The mystery is why the party's elders, and a critical mass of superdelegates, haven't stepped in to stop it. My hunch is that they're waiting till the end of the primaries, or at least past the next few big ones, but they're the rational players here who need to accurately assess the political landscape. The Clinton campaign is just acting, well, like a campaign. You don't need to think up a nefarious or complex explanation for their behavior.