Sen. Elizabeth Warren (D-MA) saw a massive fundraising surge in the last three months, lending further credence to her status as a frontrunner among a large 2020 presidential field.

In an email shared with supporters on Monday afternoon, Warren's campaign manager Roger Lau said that in the second quarter of the year, the Massachusetts Democrat raised more than $19.1 million from more than 384,000 people making more than 683,000 donations. The average contribution was $28 and, according to the campaign, more than 80 percent of second-quarter donors were first-time givers. The campaign said they now have $19.7 million cash on-hand.

That haul represents an enormous increase from Warren’s first-quarter fundraising—which, early on, raised doubts about whether her policy-centric campaign would resonate with voters. In the first quarter, Warren’s campaign said she raised more than $6 million, somewhat quieting those early concerns, especially as more than $1.4 million of that came in during the last week of the quarter.

Although, simultaneously, the campaign spent $5.2 million, in part on building up a large staffing operation in the early voting states. That hasn’t tapered off at all as Warren’s operation boasts over 300 staffers with 60 percent working in the four early-voting states.

During the second quarter, the Warren campaign had several big moments that seemingly contributed to both her polling and fundraising upswings: The senator called for impeachment early on, following Special Counsel Robert Mueller’s report; introduced her student debt cancellation plan; and publicly turned down a Fox News town hall as other Democrats chose to participate on the network.

The senator’s haul was accomplished after swearing off high-dollar fundraisers, a move her campaign has said allows her to focus on policy rollouts and near-constant grassroots events throughout the country.

Warren’s second-quarter tally puts her behind former Vice President Joe Biden, who recently announced raising $21.5 million since his late April launch, and South Bend Mayor Pete Buttigieg, who announced raising $24.8 million—the largest of the field so far.

But Warren’s second-quarter numbers beat out both Sens. Bernie Sanders (I-VT), another competitor who has rejected high-dollar fundraisers, and Kamala Harris (D-CA), whose performance in the first Democratic debate has helped propel her poll numbers upward.

Harris’ campaign recently said that she brought in nearly $12 million during the second quarter, with more than $2 million coming in the 24 hours after her strong debate performance. Warren's campaign did not share the amount of her total she earned following her debate performance on the first night of the back-to-back event.

Sanders raised $18 million in the last three months from nearly one million individual contributions.

Seeming to acknowledge that Warren narrowly beat Sanders in her fundraising total, Lau wrote in the email: “To sum it up: We raised more money than any other 100% grassroots-funded campaign. That’s big. You sent a message that Elizabeth’s vision for the future is worth fighting for. And you showed the rich and powerful that change is coming — sooner than they think.”