The next call came around 2:30 p.m., this time from an unknown number. Nielsen was at the capitol in Des Moines and let the call go to voicemail. What she heard in the one-minute recording, she said in an interview this week, came as a “gut punch.”

It was Pete Buttigieg, calling to seek Nielsen’s support now that her candidate had made the decision to “step aside.”

“What he said was not appropriate, and calling me four hours after [Booker dropped out] was not appropriate,” said Nielsen, who provided a copy of Buttigieg’s voicemail.

“It was a gut punch — like, really? He did not ‘step aside’ for you,” she said. “Like, wow, that’s some nerve right there.”

Later that night, she said, Nielsen heard from one of Booker’s field organizers who said she had already been contacted by the Buttigieg campaign to go door-knock.