A little-known Republican group is ramping up millions of dollars in funding from major US corporations such as CitiGroup and Chevron to protect the conservative stronghold on the country.

The Republican State Leadership Committee (RSLC) – which held the key to the GOP’s political takeover a decade ago – launched the Right Lines 2020 campaign last September, taglined: “Socialism starts in the states. Let’s stop it there, too.” It’s hoping to meet a $125m investment goal in an effort to retain 42 state legislature seats that the group says are key to holding power in the House of Representatives in battleground states including Wisconsin, Texas, Florida and New York.

“There’s a decade of power and a decade of dominance that’s truly on the line,” RSLC president Austin Chambers, a 24-year-old Republican operative, told Sean Spicer on his Newsmax show in March. The group recently appointed party strategist Karl Rove and ousted White House chief of staff Reince Priebus to its board.

Ahead of November’s election, Republicans face an intense Democratic challenge to unseat Donald Trump, with dark money pouring in on both sides, and consumers who are significantly more vocal and critical of corporations’ politics, especially in the wake of Citizens United. But this year’s election also coincides with the decennial census, from which demographic data helps determine the number of seats in the House. The state legislatures elected this fall will be in charge of drawing almost all the maps.

The RSLC’s goal is to get Republicans elected in down-ballot races. This can mean funding state candidates and campaign materials, including attack ads. For corporations, funneling their money through the group is a simple way to support lawmakers sympathetic to their bottom line and exert political influence.

The RSLC has gone to extreme lengths to undertake its mission, changing the political landscape in the process. In the run-up to the 2010 midterms, it led an unprecedented strategy, the Redistricting Majority Project, or Redmap, to flip legislatures in competitive states. Once in charge, Republicans manipulated district maps to their advantage, a tactic known as gerrymandering. “He who controls redistricting can control Congress,” Rove famously said in 2010.

In 2012, Democrats won 1.4m more votes than Republicans, yet Republicans maintained a 33-seat margin in the House. A 2019 USC study found that 59 million Americans now live under minority rule, where the party that receives the minority share of the vote in a state election controls the majority of seats in the subsequent state legislature. While both Democrats and Republicans gerrymander, Redmap changed the game.

Over half of the RSLC’s $17m contributions at the end of 2019 came from public companies and trade associations, according to an analysis by The Center for Political Accountability (CPA), which tracks corporate political spending. The largest single donor, however, was the conservative dark money group the Judicial Confirmation Network with $1.1m, the same group behind the nomination of conservative supreme court justice Brett Kavanaugh.

Despite the huge amount of financial support, the RSLC spends relatively little to accomplish their goal, doling out roughly $1m per state in its 2010 coup. The RSLC funnels the money towards groups on the ground that support candidates, or towards independent expenditures, including mailers, robocalls and digital and TV spots – which often veer into attack ads.

“The money doesn’t go out broadly,” said Bruce Freed, CPA president. “It goes to specific states that they see as targets of opportunity. And so the company that contributes has much greater bang for the buck.”

In the recent Wisconsin election, the RSLC spent over $800,000 on TV ads against judge Jill Karofsky attempting to portray her as soft on sex offenders. She unsuccessfully tried to block the ads, and later won the state supreme court seat. Justice Courtney Goodson also sued the RSLC in 2018 when she ran to defend her seat on the Arkansas state supreme court. The RSLC paid for a 15-second spot and mailers lambasting contributions she had received from a friend of her attorney husband, who had been a top donor to her first state supreme court campaign before they married.

But experts said the RSLC and its donors may no longer be able to fly under the radar. Once an arcane process, gerrymandering is now a contentious issue battled by grassroots movements. “Redistricting historically was something that occurred behind the scenes in smoke-filled rooms and the people didn’t pay attention,” said Michael Li, senior counsel at the Brennan Center. “Now it’s something that angers people.”

Rigged maps and their corrosive effects on democracy have drawn fierce protests in states like Wisconsin and Michigan over the past decade. Crowds came out once again last year after the supreme court’s influential ruling drawing a line between political and racial gerrymandering, putting even more pressure on the parties to win control of the redistricting process.

Consumers are also more concerned with corporate politics than they were a decade ago. Think of grocery store chain Publix, which suspended political contributions after Parkland high school students staged protests in their stores over unprecedented donations to gubernatorial candidate Adam Putnam, a self-professed “proud NRA sellout”.

RSLC contributors Citigroup, Chevron, and Dominion Energy are one of a number of companies aligning themselves with the Black Lives Matter protests, though not always directly. Altria and Dominion Energy have both pledged $5m to fight “racial and social inequality”. But these words can ring hollow.

“They can look moderate or woke to the public, even though they don’t spend their money to pursue those issues politically the same way they pursue their narrower [interests],” said Jake Grumbach, an assistant professor of political science at the University of Washington.

The Guardian reached out to the RSLC’s top five corporate donors in 2019, most of which disclose their political contributions on their websites. Chevron, Dominion and Reynolds all replied that companies contribute in a bipartisan, transparent manner according to their business interests, and declined to answer questions about Redmap. Altria and BNSF did not comment. Ultimately, Freed said, companies don’t consider the consequences of their political spending. “Corporations either turned a blind eye or they didn’t pay attention, but they’re responsible through their spending.”

While the RSLC’s counterpart, the Democratic Legislative Campaign Committee, raised only a third as much as the RSLC in 2010, the two groups are virtually neck-and-neck so far in the 2020 election cycle. “Democrats were asleep at the wheel in 2010,” Li said. “Increasingly [they] understand that they need to at least get a blocking position if not control redistricting.”

Former attorney general Eric Holder has launched the National Democratic Redistricting Committee (NRDC), backed by Barack Obama and largely funded by the Pacs of George Soros and Donald Sussman, and shored up by large contributions from leading labor unions.

Dave Abrams, the RSLC deputy executive director, called the Democrats’ pledge to stop partisan gerrymandering “flat bullshit”, and said the RSLC and its supporters were leading the fight against “radical leftists”.

But the two sides’ strategies aren’t exactly the same, said David Daley, who wrote Ratfucked, a book on gerrymandering. “The Republican strategy in 2010 was based on winning trifecta control in all of these states, recognizing that state legislatures represented an inexpensive loophole.” While Democrats have been trying to claw back power, “it’s not about taking complete control of these parties and then drawing themselves in”, Daley said. “They’re too far behind to even think about that.”

Republicans may not be able to hold onto their seats this time. In 2019, the NRDC, Holder’s organization, hit its targets in Kentucky, Virginia, and Louisiana – save for flipping the Louisiana state Senate. Democrats also won Karofsky’s seat on Wisconsin’s conservative-controlled state supreme court election in April.

“Everybody understands this is a war that has real consequences and you’ve got one shot at it,” Li said. “It’s not like we can come back and do this two years like this; this is your moment, and if you’re going to influence what the maps look like, and who’s in power for the next decade.”