Third-quarter fundraising numbers are out, and they show a notable shift toward Vermont Senator Bernie Sanders in the Democratic money primary.

The top two Democratic contenders are also beating the Republican field handily in direct campaign donations. But Republicans are cleaning the Democrats’ clocks when it comes to Super PAC funding. Tens of millions of dollars from a relatively small number of very big donors appear to be serving as a firewall of sorts as the Republican Party struggles against demographic changes that tend to favor their Democratic rivals.

On the Democratic side, there’s been a significant shift in momentum. In the previous quarter, which ended in June, the Clinton campaign took in more than three times as much as Sanders’s insurgent campaign. But the data released this week, which tracked donations through the end of September, showed Sanders raising $26.2 million to Clinton’s $29.9 million.

For the cycle, Clinton’s raised $3.7 million more than the populist from Vermont, but her campaign has also blown through more cash than any other candidate—overall, she’s spent more than Sanders has raised during this cycle—and she ended the quarter with $33 million, just $6 million more than her closest challenger.

Sanders is dominating all other candidates among small donors, which could give him a marked advantage as the primary continues. Almost three-quarters of his haul this quarter came from donors giving $200 or less, and the campaign told the Huffington Post that only 270 of his nearly 700,000 donors—less than half of 1 percent—have given the maximum individual contribution of $2,700 for the primary. That means that Sanders can go back to his donor base repeatedly as the race progresses.

Only 17 percent of Clinton’s contributions were from small donors. According to Politico, more than half of her take last quarter was from donors who are now maxed out and can’t give again until the general election gets underway.

On the other side of the aisle, Ben Carson’s ideology couldn’t be more different from Sanders’s, but his fundraising profile was similar. His campaign raised almost $21 million dollars last quarter—top among Republicans—and 60 percent of that money came from small donors. (A larger share of Donald Trump’s take, 71 percent, was from people giving $200 or less, but apparently there aren’t that many folks lining up to give a billionaire their hard-earned dollars, and his overall totals were less than those of Ohio Governor John Kasich and New Jersey Governor Chris Christie.)

Overall, direct donations to the top two Democratic candidates easily outpaced the totals of their top-tier rivals on the Republican side. At the end of the quarter, Clinton and Sanders alone had just $1 million less in the bank than all 15 GOP candidates combined, according to The Washington Post.

The picture looks very different when it comes to Super PAC dollars. Sanders has no significant Super PAC behind him. According to OpenSecrets, the group backing Clinton, Priorities USA, has raised $15.6 million for the cycle. Meanwhile, Jeb Bush’s top outside group, Right to Rise USA, has hauled in $103 million, more than four times what his campaign’s raised in direct donations. And while Texas Senator Ted Cruz’s campaign has hauled in $26.6 million overall, his many Super PACS—the guy has seven that have raised at least a quarter mil—have taken in a combined total of $38.7 million. Florida Senator Marco Rubio’s top Super PAC has also raised more money than his campaign.

In a remarkable piece of reporting for The New York Times last week, Nicholas Confessore, Sarah Cohen and Karen Yourish shed some light on the fattest of fat-cat donors through the first two quarters of this year. Their analysis found that just 358 families, and the corporations they controlled, donated well over half of the money in this election cycle, mostly through Super PACs, and “the vast majority” of that cash went to Republicans.

The reporters focused in on the top 158 families, who donated a whopping $176 million through June. These mega-donors, according to The Times, are “overwhelmingly white, rich, older and male,” and 138 of them are conservative, “contributing tens of millions of dollars to support Republican candidates who have pledged to pare regulations; cut taxes on income, capital gains and inheritances; and shrink entitlement programs.”

If this trend continues through the 2016 cycle—with Democrats leading the GOP in direct campaign contributions while a relatively small number of large donors fund Republican Super PACs—it will set up an interesting dynamic. Super PACs can raise vast sums of money without disclosing their donors, but they also come with certain disadvantages for a campaign. While the rules against campaigns coordinating with their outside groups are hardly being enforced, the PACs can’t pay for campaign infrastructure—things like staff, offices, or a candidate’s travel. Wisconsin Governor Scott Walker learned this lesson the hard way, dropping out of the race with little money in his campaign coffers, although his goofily named Unintimidated PAC had raised $20 million, second only to Jeb Bush’s.

And while they can blanket the airwaves with ads, broadcast media also charge Super PACs a premium for advertising time, sometimes getting up to four times as much as they did from campaigns directly during the 2012 cycle, according to Bloomberg Business.

It will be interesting to see whether these trends persist as we get closer to actual votes’ being cast. Did Hillary Clinton’s strong performance in last week’s debate soothe jittery donors enough to for her to regain the fundraising lead she enjoyed in the second quarter, or will her maxed-out donors prove to be a drag on her numbers? Will the GOP field shrink, and the remaining candidates get a boost in direct fundraising, or will they continue to be kept afloat with a boatload of Super PAC money? We’ll know the answers in February.