The political network founded by the billionaire industrialist brothers Charles and David Koch has endorsed Nikki Haley in the Republican presidential nominating contest, giving her organizational muscle and financial heft as she battles Gov. Ron DeSantis of Florida to be the top rival to former President Donald J. Trump.
The group announced its plans in a memo on Tuesday.
The commitment by the network, Americans for Prosperity Action, bolsters Ms. Haley as the campaign enters the final seven weeks before the Iowa caucuses. Since the first Republican primary debate, Ms. Haley has steadily climbed in polls, even as Mr. DeSantis has slipped. Mr. Trump remains the dominant front-runner in the race.
“In sharp contrast to recent elections that were dominated by the negative baggage of Donald Trump and in which good candidates lost races that should have been won, Nikki Haley, at the top of the ticket, would boost candidates up and down the ballot,” reads the memo from Emily Seidel, a senior adviser to Americans for Prosperity Action, who adds that Ms. Haley would win “the key independent and moderate voters that Trump has no chance to win.”
The memo goes on to say that the country “is being ripped apart by extremes on both sides,” adding: “The moment we face requires a tested leader with the governing judgment and policy experience to pull our nation back from the brink. Nikki Haley is that leader.”
The group laid out polling describing the shift in the race toward Ms. Haley in a separate memo. On a separate call with reporters, the senior adviser who presented the polling, Michael Palmer, said that Mr. DeSantis’s support over the course of the year had dropped “precipitously.”
Ms. Haley, who has described Mr. Trump’s time as past, has gained support from donors and elite opinion-makers, many of whom describe her as the best alternative to Mr. Trump.
But Ms. Haley’s campaign does not have the organizational strength that Mr. DeSantis does, thanks to work the super PAC affiliated with his campaign has been doing for much of the year.
The endorsement from the super PAC established by the Koch brothers could help change that. It will give her access to a direct-mail operation, field workers to knock on doors and people making phone calls to prospective voters in Iowa and beyond. The group has money to spend on television advertisements, as well.
“I’m honored to have the support of Americans for Prosperity Action, including its millions of grass-roots members all across the country,” Ms. Haley said in a statement. “A.F.P. Action’s members know that there is too much at stake in this election to sit on the sidelines.”
The Koch network’s backing helps fuel Ms. Haley’s momentum heading into the final weeks before voting begins. And it’s a blow to Mr. DeSantis as he tries to maintain to donors that he is the only person who can beat Mr. Trump if the contest eventually whittles down to the former president and one other contestant.
Americans for Prosperity Action has been among the country’s largest spenders on anti-Trump material this year, buying online ads and sending mailers to voters in several states, including Iowa, New Hampshire and South Carolina. All told, the group has spent more than $9 million in independent expenditures opposing Mr. Trump.
One mailer in Iowa, paid for by the group, shows images of Mr. Trump and President Biden and reads, “You can stop Biden … by letting go of Trump.”
But so far, none of that spending has benefited any of Mr. Trump’s rivals, who have been busy battling one another.
The Koch network is well financed, raising more than $70 million for political races as of this summer. On a press call about the endorsement, officials declined to say how much money they would budget toward helping Ms. Haley.
The group has been committed to opposing Mr. Trump’s return as leader of the Republican Party. In a memo in February, Ms. Seidel, who also serves as the president of Americans for Prosperity, the political network’s parent group, wrote: “We need to turn the page on the past. So the best thing for the country would be to have a president in 2025 who represents a new chapter.”
Steven Cheung, a spokesman for Mr. Trump’s campaign, said in a statement, “Americans for Prosperity — the political arm of the China First, America Last movement — has chosen to endorse a pro-China, open borders, and globalist candidate in Nikki ‘Birdbrain’ Haley,” adding that no amount of “shady money” would stop Mr. Trump from winning the Republican nomination and the election.
Over the past few years, the Koch network has spent tens of millions of dollars opposing the foreign policy views that Ms. Haley has espoused. She has been among the most hawkish in the Republican presidential field on aid to Ukraine in its fight against the Russian invasion, while the Koch-backed group Concerned Veterans for America has opposed American involvement in that conflict.
Ms. Haley has also criticized the U.S. withdrawal from Afghanistan, a policy change that the Koch network campaigned aggressively to bring about. And she has advocated military strikes in Iran, while the Koch foreign policy operation has opposed military action against the country.
Mr. DeSantis’s campaign has had upheaval in recent days, including the resignation of the chief executive of his super PAC. Mr. DeSantis, who has polled solidly in second place behind Mr. Trump since he entered the race this year, has seen his standing drop in surveys. He has struggled to connect with voters, and efforts to lift him — including a recent endorsement by Iowa’s governor, Kim Reynolds — have yielded little return in polling.
His team tried to throw cold water on the endorsement before it was even announced.
“Every dollar spent on Nikki Haley’s candidacy should be reported as an in-kind to the Trump campaign,” Andrew Romeo, a DeSantis campaign spokesman, wrote on X, formerly known as Twitter, 30 minutes before the press call.
“No one has a stronger record of beating the establishment than Ron DeSantis, and this time will be no different,” he wrote.