A reader sums it up well:
I have always qualified my prediction of a victory by Democrats by saying that I could not rule out the possibility that they would seize defeat from the jaws of victory. To my amazement, they seem to be actually doing so. One could not write a scenario more favorable to Republicans than the one playing out. If Hillary wins, I think the party will be so damaged that she will definitely lose to McCain. Although Obama would still be favored over McCain, Hillary is unwittingly showing the Republican how to beat him and testing out the strategy that McCain will be able to use against him. There is no question that she has drawn some blood. And the longer she stays in the race the more blood she draws, as well as draining Obama’s money and time from focusing on McCain. When you consider that McCain, for all his flaws, was always the only Republican who could win this year, I almost have to wonder if God is a Republican after all.
Never, ever under-estimate the ability of the Democratic party to screw it up. They should have won this election easily. Now, the odds clearly favor McCain. And if it's him versus the Clintons, after all they have revealed about themselves in this primary season, many, many Independents will not be particularly torn.