A few days ago, Peggy Noonan summed up why she thought Hillary has been able to muster a comeback of sorts, but also paints a vivid picture of what it would mean for her to succeed: 

She kept her own spirits up to the point of denial and worked it, hard, every day. She is hardy, resilient, tough. She is a train on a track, an Iron Horse. But we must not become carried away with generosity. The very qualities that impress us are the qualities that will make her a painful president. She does not care what you think, she will have what she wants, she will not do the feints, pivots and backoffs that presidents must. She is neither nimble nor agile, and she knows best. She will wear a great nation down.

Very well said, Peggy.