Allies say Warren’s demeanor changed after disappointing results rolled in from gray and snow-covered New Hampshire. Already upset with herself for a lackluster New Hampshire debate and down about her disappointing third-place finish in Iowa, she made a case to her staff that this was the time to fight.

“There’s going to come a time when it is clear what’s going to happen in this contest, but that time is not now,” she said, according to a person familiar with the call who spoke on the condition of anonymity because the person was not authorized to discuss it. “We are nowhere near that moment. We are not close. We’re not even within shouting distance.

“These are the moments we find out who we are.”

Her new approach might be too late. Nearly as many Nevada caucus-goers participated in early voting before her breakout debate as the total turnout four years ago, meaning a massive chunk of the electorate here weighed in before seeing Warren sparkle onstage. Hundreds of thousands already have cast their ballots in California, the top delegate prize on March 3.