The Politico offers that analysis.
I have never been enamoured of the manner in which Clinton has managed her campaign. It is not simply the concept of inevitability that has done her in, but her reliance on staff so fiercely loyal to her, that they cannot operate effectively if they fawn over their boss. Add to that a reliance on consultants that seem wedded to their own prowess than providing good services to the campaign.
Every campaign has set backs and it is the manner in which the staff and the candidate respond to them that sets them apart. I don't think Obama is right for this country, but he has confronted all the gaffes with an organization that is far more disciplined than anything Hillary Clinton could hope to cobble together.
If you can't manage a campaign, how can you manage a country?