The fundraising success of Sanders, whose average donation was $18, is the latest sign that he has been able to retain many left-wing supporters that the Warren campaign was hoping to peel away.

Realizing that her fundraising numbers were likely to underwhelm, the Warren campaign sought to lower expectations in advance. In a number of emails to supporters over the past week, the campaign admitted it was behind its past fundraising pace and set a goal of raising $20 million — below its last quarter figure.

The campaign then tried to spin the $21.2 million as a victory. “I'm excited to share some great news with you,” campaign manager Roger Lau wrote in an email to supporters. “Thanks to supporters like you who stepped up and chipped in, we beat our goal.”

Asked about her rivals' fundraising numbers Thursday, Warren told reporters that she was "deeply grateful" to her contributors and that she "didn't spend one single minute selling access to my time to millionaires and billionaires. I did this grassroots."

The dip in fundraising is a potentially ominous sign for the Warren campaign going into the last weeks before the Iowa caucuses and other early state contests. Lau, however, argued that the campaign was entering the final stretch with a surge of money, including its best single-day fundraising total on the last day of the quarter with $1.5 million raised.

Warren has bet that her no-fundraiser approach could not just free up her time, but also be a useful attack to deploy against her rivals. Over the past several months, Warren has increasingly tried to draw attention to Buttigieg and Biden’s fundraising practices and attempted to connect it back to her core message that the rich and powerful have rigged the system.

“If Democratic candidates for president want to spend their time hobnobbing with the rich and powerful, it is currently legal for them to do so — but they shouldn’t be handing out secret titles and honors to rich donors,” she said in a statement before a debate in October.

In December, she took on Buttigieg more directly and called on him to release his bundlers, and open up his fundraising events to reporters in addition to highlighting a recent event that took place in a wine cave. “Billionaires in wine caves should not pick the next President of the United States,” she posted on Instagram after the most recent debate.

Buttigieg ultimately did open his events to press and reveal his bundler list but countered that Warren had raised money in similar ways when she was running for Senate. It’s unclear if Warren’s attacks have helped her cause as there have not been many early state polls over the holidays.

Lau didn't jab any of Warren's rivals Friday, however. Instead, he tried to draw the contrasts more subtly. "Elizabeth didn't host any private events to raise money from wealthy donors behind closed doors," he wrote.

Like Biden, Buttigieg, and Sanders, Warren did not disclose how much money she has on hand. The campaigns do not have to make such a disclosure until January 31 — just days before the Iowa caucuses.

“We hit our goal for 2019, but it's 2020 now, and we've got new, must-hit daily targets,” Lau wrote, adding that “the first votes are just a few weeks away.”