WASHINGTON – The Democrats who captured the House by flipping 43 districts from red to blue in the November election received on average more than half of their large-dollar campaign funds from outside their states.

By contrast, defeated Republicans in those districts collected only about one-third of their itemized funds from outside their states, according to a USA TODAY analysis of funding data collected by the nonpartisan Center for Responsive Politics.

The money that poured into House races from out-of-state donors was another example of the nationalization of the 2018 midterm elections that were partly a referendum on President Donald Trump's first two years in office.

Analysts said the data reinforced other signs that opposition to Trump helped to motivate Democratic donors.

The data did not capture all small-dollar donations, which don’t have to be identified by donor but which were maximized by Democrats this year. One fundraising vehicle, for example, allowed Missouri freelance writer Robin Burks to give $4.68 a month – or 1 cent to each of the 435 House races and 33 Senate races contested in November.

Top large-dollar contributors to the winning Democrats included not just regular Democratic mega-donors such as Florida financier Donald Sussman and billionaire environmentalist Tom Steyer.

"We were all in on flipping the House," said Steyer, who spent millions of dollars mobilizing voters. "That was our No. 1 bottom line."

They also included Seth Klarman, head of a Boston-based private investment firm who used to give to primarily Republican causes.

Top donors included Barbara Karplus, a semi-retired teacher from California with little history of political giving, who cut back on her classroom hours to focus on researching which candidates to support. Among those she backed were 30 of the Democrats in the districts that flipped. She gave them more than $100,000 combined.

Karplus, 63, said she asked herself if it was better for her children to inherit money when she dies or a country that’s “maybe a reasonable place to live.”

“And there’s no guarantee I’m leaving them a better country,” Karplus said. “But all I can do is work toward it.”

The 43 districts Democrats flipped, minus the three they lost, gave them control of the House where they will be a check on Trump next year. (The results on one GOP-held seat have not been certified while officials investigate possible election fraud.)

Republicans expanded their narrow control of the Senate by two seats, boosted by the fact that so many of the senators up for re-election this year represented states Trump won in 2016.

The House fundraising figures show how much energy there was on the Democratic side.

The Democrats who flipped GOP seats raised a combined $236 million compared with $142 million raised by the Republicans. On average, about 51 percent of itemized contributions to Democrats came from outside their states. That’s despite the fact that House candidates typically draw the most money from in-state donors, according to the Center for Responsive Politics.

“Democratic donors had an urgency and desperation that they’ve never had before because they dislike President Trump so intensely,” said David Wasserman, who tracks House races for the nonpartisan Cook Political Report. “That allowed Democrats to raise money all over the country.”

Only those who give more than $200 have to be identified in campaign filings. Donors can’t directly give more than $2,700 for a candidate’s primary and $2,700 for the general election.

Still, at least 20 people gave more than $100,000 to the winning Democrats in the flipped districts, USA TODAY calculated.

High on the list was Klarman, the former GOP donor from Boston who told The New York Timesin September that he gave millions of dollars to Democrats this year to “act as a check and balance” on Trump. Some of his millions went to super PACs, which can accept unlimited contributions, to support House and Senate Democrats.

Wasserman said one element of the election that hasn’t gotten nearly enough attention is that Trump repelled wealthy voters away from the Republican Party with such velocity that Republicans risk letting Democrats become the party of the rich.

“Democrats now dominate elite ZIP codes that were Republican as recently as a decade ago,” he said.

Silicon Valley has long been friendly to Democrats, but some donors were particularly active this cycle.

“I’ve never supported so many candidates,” said Laura Lauder, a venture capitalist from Atherton, California, who gave more than $100,000 combined to Democrats in the flipped districts.

Lauder was particularly motivated to help the record number of women running for Congress, including hosting fundraising events for candidates such as Abigail Spanberger, who will be the first woman to represent a central Virginia district that has been in Republican hands since 1971.

“I was very mobilized and incensed – the word is incensed – by Trump,” Lauder said.

Jubilant at the results, which kept getting better for Democrats as more races got called after election night, Lauder chuckled at a joke making the rounds that although most elections are like Christmas, this one was like Hanukkah “because it kept giving every night.”

Karplus, the California teacher, was afraid to watch the returns as they came in, fearing a repeat of 2016. Instead, she and her husband went to the movies.

When they did start tracking results, they pulled out the spreadsheet they’d compiled of the candidates they’d backed.

Karplus said she'd made political contributions only twice in her life before the 2016 elections. Upset by what she saw as an intransigent Congress and disturbed that the Senate refused to consider President Barack Obama’s Supreme Court nominee, Karplus started looking for candidates to support that year. After Trump was elected and Republicans she viewed as obstructionist kept control of Congress, she took it even further.

Reducing her time in the classroom so she could focus on her own homework, Karplus used groups such as No Labels and the Problem Solvers Caucus to help her find candidates she hoped would work across the aisle to get things done.

“I’m fired up,” she said. “But I’m fired up for rationality.”

For those unable to do as much candidate research as Karplus did, there were groups such as It Starts Today, which enabled people to support every Democratic nominee for the House and Senate through a single monthly donation.

Burks, the freelance writer from Missouri who gave $4.68 a month, said that a few years ago, she might have been concerned about which Democrat won in a particular race. No longer.

“We are now in a position where we need party unity more than anything,” she said. “As long as my money is going to a fellow Democrat, I am going to be happy.”

The donor vehicle she used was started by one of the people who created ActBlue, a Democratic fundraising tool that’s been around since 2004 but was particularly powerful this election.

The $1.6 billion given through ActBlue to Democratic candidates and causes this year was double the amount distributed in the 2016 election cycle.

More than half of all funds raised by all House candidates came to them through ActBlue, according to the group.

The nonprofit group tries to make it as technologically easy as possible for people to donate either to a specific candidate or, for example, to donate to a fund that would go to the eventual Democratic nominee in a district. (That was a particularly popular option when donors wanted to give last year to the “nominee fund” against any Republican who voted to repeal the Affordable Care Act.)

“Any time any Republican was saying things, particularly talking about health care, you would see (donation) spikes around those races,” said Erin Hill, ActBlue’s executive director.

In the 43 flipped districts, the more than $44 million that Democrats raised in small-dollar donations was three times the amount Republicans collected in amounts of $200 or less. Democratic candidates got on average 19 percent of their funds in small-dollar contributions compared with 9 percent for Republicans.

“Seeing that a bunch of these candidates who flipped the seats were heavily funded from these grass-roots contributions, I think (that) did make the difference,” Hill said. “That’s why you see Republicans talking about it so much.”

As Republicans complained that they needed an ActBlue equivalent, freshman GOP Rep. Jim Banks of Indiana launched StopSpeakerPelosi.com to help the most vulnerable Republican candidates.

That didn’t happen until late October.

Besides, Wasserman said, ActBlue wasn’t Republicans’ problem.

“It was Trump,” he said.

It’s unclear how much House Democrats will go after Trump next year. Opinions among Democrats – and their donors – are divided.

In addition to giving more than $100,000 directly to the successful Democratic candidates in House districts, Steyer spent tens of millions on other initiatives, including his "Need to Impeach" Trump campaign. Supporters wrote 1.6 million postcards to voters in swing districts to encourage them to get to the polls.

Though Steyer said there’s enough evidence for the House to impeach Trump, Lauder said that wasn’t the reason she gave to the winning candidates – as much as she opposes Trump. Impeachment, she said, would be an elongated process that would further divide the country and detract from getting other things done.

“The election in 2020 will be the best and most appropriate place for Americans to decide whether or not President Trump should be re-elected or removed from office,” she said. “And frankly, we have work to do.”

Contributing: Bill Theobald