(Bloomberg Businessweek) — Democrats are hoping a blue wave of support will carry them to victory in this fall’s elections. In the meantime, they’ve caught a green wave of cash—the torrent of money pouring into Democratic campaign coffers helped 73 House candidates outraise Republican incumbents and opponents in races for open seats in the second quarter, a Bloomberg analysis of Federal Election Commission data shows. The more candidates the Democrats can field with the means to run competitive races, the larger the potential blue wave could be, if, as most experts anticipate, a motivated anti-Trump electorate shows up to vote in November. Democrats need to pick up 23 seats to retake control of the House.

The surge of Democrats who raised more money than their GOP opponents last quarter is testimony not only to widespread antipathy to Trump among liberals and many independents, but also to the fundraising acumen of the party committee and many of the new grass-roots groups that sprang up in the wake of Trump’s victory.

Since Trump’s election, Democratic enthusiasm has been apparent in all sorts of ways: the proliferation of anti-Trump marches, the record number of new candidates running for office, increased turnout in primaries and special elections, and surveys showing left-leaning voters more invested in November’s election than their counterparts. That energy has also translated into dollars. In the second quarter of this year, non-incumbent Democratic House candidates raised more than three times the amount they did in the same period in 2014. That works out to an average of $151,000 per candidate, compared with $101,000 in 2014.

“We can see the intensity by how many more campaigns from the Democratic side than the Republican side reached out to us,” says Steven Spinner, chief executive officer of RevUp Software Inc., a nonpartisan data analytics fundraising company. “We’re getting far more inbound calls and seeing accelerated deployment and usage among Democrats, which correlates with the public fundraising results we see at the end of each quarter.”

Throughout his presidency, Trump, along with many political analysts, has marveled at the unbending loyalty he commands among a core group of Republican voters, no matter how outrageous his words or actions. As Trump quipped during an Iowa campaign stop in 2016, only slightly exaggerating, “I could stand in the middle of Fifth Avenue and shoot somebody, and I wouldn’t lose voters.”

But Trump has had a corollary effect, less noted but no less galvanizing. He’s steeled the determination of an equally committed opposition, happy to write checks to Democratic candidates across the country. “The best fundraiser Democratic candidates have had is Donald Trump,” says David Wasserman, House editor for the nonpartisan Cook Political Report, whose recent analysis favors Democrats to win back control of the House. “A propensity of negative feelings is driving donor decisions, even in districts where we don’t think campaigns are in striking distance yet.”

This summer has seen a steady stream of Republican-held districts becoming more competitive. In July alone, Wasserman moved 10 House races toward the Democrats, while moving just two toward Republicans, a trend mirrored in other expert forecasts. Because of a raft of retirements, including House Speaker Paul Ryan’s, Republicans are also defending 42 open or vacant seats, which are typically harder for the incumbent party to hold, a record number since at least 1930. In 20 of those open districts, the Democratic candidate outraised the Republican. Strategists and organizers say the steady growth of Democratic enthusiasm is driven mainly by anger at Republicans. “Every Trump action has an equal and opposite reaction on the Democratic side,” says Alfred Johnson, co-founder and CEO of MobilizeAmerica Inc., an online platform that connects activists and Democratic campaigns. “Every new outrage, whether it’s taking children from their parents at the border or propping up a dictator in Helsinki, is causing a proportional spike among people on our side determined to make a difference.”

Every cycle, the Democratic Congressional Campaign Committee, the party’s campaign arm, tries to steer donors to a slate of races it considers most winnable. In the past, activists and small donors haven’t always agreed with the party establishment. A perennial complaint among strategists was that donors flocked to a handful of “celebrity” candidates, such as Elizabeth Warren or Georgia House candidate Jon Ossoff, showering them with resources while other candidates were left wanting. This cycle looks to be different, at least in the House, as establishment and grass roots are in general agreement on the critical races. As a result, money has flowed to dozens of competitive districts—an approach more analogous to index investing than stockpicking, as donors spread their bets across a broad range of candidates, instead of backing a popular few and counting on a perfect performance from them.

This approach has been facilitated by several new grass-roots groups that have been sophisticated about how they encourage their supporters to give. Swing Left, a group founded just after the election, is focused on battleground districts, rather than candidates. “We launched with the idea of starting the 2018 campaign immediately and thought the House would be the thing,” says Ethan Todras-Whitehill, the group’s co-founder. Swing Left recognized many of the closest races would be easily identifiable and didn’t wait for a nominee to emerge. “We realized you can raise money and essentially hold it in escrow for an eventual nominee,” says Todras-Whitehill. The group has so far raised about $5 million from 55,000 donors, he says.

More recently, Swing Left and other groups have directed donors to cash-strapped nominees newly emerged from competitive House primaries in an effort to fill their war chests for November. “What we’re seeing in 2018 is the emergence of the amateur political strategist,” says Wasserman. “People who are Democratic activists, who want to plug holes on the fundraising map and leave nothing to chance.”

Although the green wave makes Democrats more competitive this fall, there’s no guarantee it will wipe out Republicans’ control of Congress. Incumbency carries many advantages. Despite their strong fundraising performance, for instance, only 22 of the 73 Democratic challengers who outraised their Republican opponents last quarter finished with more cash on hand. While the influx of first-time candidates has thrilled liberal activists, these upstarts are untested in the rigors of a general election campaign. Dan Eberhart, a GOP fundraiser, says while Democrats have a financial advantage in some races, the Republican National Committee has still raised more money this cycle than the Democratic National Committee: $213 million to the DNC’s $109 million.

Even so, Democrats’ success in generating dollars, especially from small donors, is a bullish sign for a party poised to make big gains on Election Day. “The two things donors ask us is ‘Who needs my money the most?’ and ‘Where will it go the farthest?’ ” says Todras-Whitehill. “Those are questions we can easily answer.” —With Bill Allison