In a fund-raising shocker, supporters of Senator Bernie Sanders’s presidential campaign have given an impressive $26 million-plus in small-dollar donations in the last three months, putting his funding at the pace of Hillary Rodham Clinton’s formidable machine.

Mrs. Clinton netted more than $28 million in the quarter while she and her husband, Bill, worked dozens of Democratic fund-raising events that aimed to raise the federal maximum of $2,700 per primary donor. Mr. Sanders, running as an insurgent social democrat, attended far fewer fund-raisers and relied mainly on Internet donations, which his aides said average about $30. The Clinton campaign said it holds its own among moderate-income donors, with 93 percent of its total coming from donations of less than $100.

Mr. Sanders has made a campaign theme of skewering the big-dollar, “super PAC” machinery of modern politics, and his donors clearly are responding. He reported 1.3 million online contributions from 650,000 different donors, running ahead of the Obama campaign’s 2008 record for small-dollar gifts. Mrs. Clinton’s campaign reported 250,000 donors three months ago but no new total for the latest quarter.

Her campaign insisted it was on target to raise $100 million this year, while the Sanders campaign said it had already reached its $40 million goal for competing in the Iowa caucus in February. In the Republican primary, Ben Carson, campaigning as a nonpolitician, reported an impressive $20 million for the quarter from more than 350,000 donors.