Elizabeth Warren raised $24.6m over the past three months, relying largely on a massive small donor operation to solidify her status as a leading contender for the 2020 Democratic presidential nomination.

The Massachusetts senator’s haul, announced on Friday, is just less than the $25.3m her chief liberal rival, Senator Bernie Sanders of Vermont, posted during the third quarter. But together, the fundraising numbers illustrate the financial strength of the Democratic party’s most progressive wing and a rejection of more traditional approaches to pressing donors for money.

The White House hopefuls who have relied on frequent high-dollar fundraisers reported numbers that lag behind Sanders and Warren. Former vice-president Joe Biden said Thursday he raised $15.2m during the third quarter. Senator Kamala Harris of California reported $11.6m during the same period. Pete Buttigieg, who has combined small donors with traditional fundraisers, raised $19.1m.

“This means our grassroots movement is in an incredible position – to double down on our investments in grassroots organizing, to keep getting Elizabeth’s plans for big, structural change in front of more caucus-goers and voters, and to bring more people into this fight,” Warren’s campaign said in a statement.

Warren and Sanders have consistently attracted armies of small donors, many of whom contribute online. Warren’s campaign said its quarterly totals came from 509,000 donors offering 943,000 donations. Her campaign has $25.7m cash on hand.

“Progressive politics are winning politics, period,” Stephanie Taylor, co-founder of the not-for-profit Progressive Change Campaign Committee, said in a statement praising both Warren and Sanders’ fundraising prowess. “They are clearly the strongest, most electable candidates.”

After a sometimes rocky start to her campaign at the beginning of the year, Warren is in a close race for first place with Biden, according to several polls of voters nationally and in key early states. She has surpassed Sanders in many of these surveys.

Warren has argued that by shunning big-dollar fundraisers and large donations, she has had more time for things like staying hours after rallies to take “selfies” with thousands of attendees. She has drawn huge crowds lately – including on Thursday night in San Diego, when the campaign estimated that 8,500 people thronged a grassy, downtown park off the Pacific Ocean to cheer her plans for a “wealth tax” on the fortunes of the richest Americans and vows to break up powerful banks and tech giants like Facebook.

The Iowa caucuses that kick off the presidential nomination process are now less than three months away – meaning all campaigns are under pressure to show they can excite both donors and would-be voters and seize momentum. Warren says she’s doing both.

Still, the ultimate Democratic nominee would face a formidable opponent in President Donald Trump who, in partnership with the Republican National Committee, raised $125m during the third quarter.