Do not count Hillary Clinton out. She has powerful protectors, and the public's memory for a scandal can be soothed into oblivion with deft treatment by the Main Stream Media.
Remember Obama and Bill Ayres? And Jeremiah Wright? And Tony Rezko? And Alex Giannoulias? Remember the flap the Right attempted to excite over his secretiveness about his college transcripts and involvement with socialist organizations? Remember the discovery that he styled himself as Kenyan born when Dreams From My Father was published? Remember "57 states?" Remember "Can't I just eat my waffle?" He was elected anyway.
Perhaps Obama will add fuel to the fire by condemning her decisions and a posteriori self-justifications; that would probably reduce Hillary's chances below the threshold of negligibility. But very few other developments would do so. Perhaps if she were photographed while engaged in a sex act with Huma Abedin, but that's all I can think of just now.
Say what you will about the Clintons; they're very hard to knock out.
Any anointed Democrat will be hard to knock out. The only reason we didn't have a John Kerry presidency is because the media hadn't yet figured out that it could ignore conservative media and keep 80% of Americans in the dark.
Instead of circling the wagon's once Rathergate broke open, they assumed that once Rather was so obviously busted by conservative media that he was indefensible, and the rest of the media sought to distance themselves from his lie. They gave credibility to the conservative blogosphere by ceding its narrative (which happened to be the truth). They ridiculed Rather's "fake but accurate" explanations. They took it on the chin, and decided it wasn't worth the fight. They also would never allow the Swiftboat accusation to make front-page news. Both those huge news stories worked against Kerry and for Bush.
But they learned quickly that they didn't have to give credence to anything they didn't want to, and thus we have Obama. They would never allow such damaging stories to become news now. Not with the anointed candidate.
We must assume from heretofore, that the media will be blatantly all-in with whomever the Democrat nominee happens to be. Not just all-in, as in obviously rooting, but all-in, as in blatantly lying and covering, ignoring anything damaging from the conservative media.
