She may also be surging in New Hampshire: an Emerson College poll released Tuesday showed her rocketing into second place there, with 21% support, more than doubling her total from February, while Sanders tumbled to third in the survey.
In interviews with 44 New Hampshire Democrats last weekend, those behind Biden frequently turned to sober words like trust and experience, and calculated that he is best positioned to win swing voters. Much of his visible support at the Manchester convention came from a bloc of union firefighters. Sanders loyalists praised his unstinting message and leadership in moving the party leftward.
Warren supporters said they could relate to her backstory, growing up poor in Oklahoma, being a single mother and going on to teach at elite law schools after attending Rutgers Law. They described her as detailed and progressive, but with a more upbeat and practical style than Sanders.
"We need energy, and she gave it to me," said Diane Foley, 70, said in Portsmouth as she recounted seeing Warren earlier in the campaign.
In an online poll of Democrats in 18 early voting states, 46% would be excited by a Warren nomination, against 38% for Sanders and 29% for Biden, CBS/YouGov found. More Democrats named her as their first choice than anyone else (though she was only 1% stronger than Biden), according to the survey, completed last week.
However, she trailed Biden and Sanders in three of the first four primary states, and polling by Morning Consult shows that Biden supporters are slightly more likely to pick Sanders as their second choice than Warren.
The liberal senator has built her campaign around a relentless public schedule (129 town halls, she said) and a stream of detailed policy ideas, explained in human and digestible terms by a former law professor. In her speech Saturday, Warren said the first $50 million of anyone's assets would be free from her tax plan -- and wiped her brow for comic effect.
"There's a joyfulness that comes with Warren as opposed to the straight doom and gloom with Sanders," said John Lapp, a Democratic consultant based in Washington, D.C.
Sanders and Warren appear on a collision course as they compete to represent the party's liberal wing and to win New Hampshire, the second state in the nominating contest and one they both claim as a neighbor.
Still, the two have avoided conflict with one another, endorse many of the same policies and many of their supporters in New Hampshire expressed admiration for both.