NYT has Hillary and her aides thinking that if she doesn’t take both Texas and Ohio on March 4, she’s toast:

Mrs. Clinton held a buck-up-the-troops conference call on Monday with donors, superdelegates and other supporters; several said afterward that she had sounded tired and a little down, but determined about Ohio and Texas.

They also said that they had not been especially soothed, and that they believed she might be on a losing streak that could jeopardize her competitiveness in those states.

“She has to win both Ohio and Texas comfortably, or she’s out,” said one superdelegate who has endorsed Mrs. Clinton, and who spoke on condition of anonymity to share a candid assessment. “The campaign is starting to come to terms with that.”

She could do that, but Obama clearly has generated the perception (at least) of momentum. He’s the clear-cut candidate of the future; I suspect that a lot of her appeal lies with those who remember the ’90s fondly and think, or hope, that a President Hillary might be able to recreate those relatively golden times.