Near the debate's end, Obama delivered a gracious homage to Hillary. It may well have been sincere--but it also sounded like a man bidding his rival farewell.

"It's been an honor to campaign," Hillary said wistfully a few minutes later. She then added, almost as an afterthought: "I still intend to do everything I can to win. But it's an honor." I really get the sense here of someone on the brink of giving up. I'll be surprised if she tries to carry on after a loss in either Ohio or Texas.

--Michael Crowley