The Washington Post on Saturday reported that Hillary Clinton has launched “an intense press to stockpile campaign dollars in the final days of the quarter, aiming to build a war chest big enough to eclipse what is expected to be a healthy fundraising haul by Sen. Bernie Sanders of Vermont.”

Say what? The Clinton campaign is pressing to match Bernie’s grassroots fund-raising totals? Sanders has surged to a stunning lead in the early polls in New Hampshire and is continuing to gain in Iowa. Clinton has suffered a terrible summer, with polls registering growing disapproval.

Now Sanders may demonstrate that, in the new age of social media, it is possible to raise enough money from small donations largely over the Web to be competitive in a presidential race. Hillary raised a record $46 million in the last quarter (the first reporting period since her announcement), with 16.8 percent coming from donations of $200 or less. Bernie raised $15.2 million, more than any Republican contender, with 68 percent from donations of $200 or less. Now his totals are forcing the Clinton campaign to react.

The Clinton push, as the Post reports, featured five fundraising parties in and just outside of New York City on Thursday and Friday, “including one at the home of the wealthy corporate take-over chieftain who was a model for the Wall Street procedural ‘Barbarians at the Gate.'”

Hedge-fund millionaire Cliff Robbins hosted a Friday evening event in Greenwich, Conn. Robbins runs the hedge fund Blue Harbor Group, and has made a fortune in junk bonds and hostile takeovers. He earned notoriety as architect of the $30 billion leveraged buyout of RJR Nabisco in 1988 that was the basis of the best-selling book and HBO movie, “Barbarians at the Gate: The Fall of RJR Nabisco.”

The attendees of the Clinton fundraisers will be pressed to contribute the maximum of $2,700 per person to her campaign (and separately to make big-buck contributions to her “independent” super PAC, Priorities USA Action). In these cases, each is encouraged to ante up that sum for each adult member of the family, and frequently in the name of various retainers as well.

Wooing big donors for donations inevitably gives the appearance of corruption, a point that Donald Trump has hammered home in the Republican debates. Not surprisingly, dozens of deep-pocket donors have given to both the Jeb Bush and the Hillary Clinton campaigns or super PACs. Hillary’s super PAC is even more reliant on deep-pocket donors, openly soliciting gifts of a million dollars or more. Sanders refuses to set up a big-donor super PAC to support his campaign, so Clinton will retain a major lead in total campaign war chest.

Clinton argues that while she is for putting restrictions on the flow of unregulated big money into politics, she can’t “unilaterally disarm.” Now Sanders may be on verge of demonstrating that a populist candidate can compete – and compete well – while refusing to rely on what he calls the “billionaire class.”

Relying on the wealthy exacts a price. Democratic billionaires tend to be socially liberal. Many agree that the tax breaks for the rich have reached obscene levels. Clinton has called for ending the absurd carried interest deduction that Robbins and other hedge fund operators pocket. She’s put forth a complicated plan to reduce the tax break given to investor’s income over workers’ incomes. But there are limits.

Sanders can call for breaking up the big banks. Clinton does not. Sanders supports Elizabeth Warren’s call for a new Glass-Steagall Act to curb banker gambling with government guaranteed deposits. Clinton does not. Sanders calls for ending the tax break for corporate profits harbored abroad. Clinton does not. Sanders opposes our current ruinous trade policies. Clinton has withheld judgment. Sanders is for a financial transaction tax to limit the Wall Street casino. Clinton is not. Sanders is for major increases in top-end taxes. Clinton’s position is yet to be unveiled.

Money talks. Now Sanders may be able to demonstrate not only that his populist message enjoys broad popular support and can spark a movement for change, but that his small donor grassroots fundraising can support a competitive challenge to big-money politics.

The fundraising quarter ends on September 30. Clinton will be doing a whirlwind of big-dollar events across the country, while her campaign pushes hard for online contributions. Sanders will be campaigning, while his organization launches appeals to citizens across social media. The quarter results will be revealed in mid-October. That they might even be close represents a potential sea change in American politics.

Robert Borosage is co-founder of Campaign for America's Future, where this post first appeared.