NEW YORK — Steve Bannon’s war on the GOP establishment has caught the party’s most powerful donors in the crossfire.

Deep-pocketed supporters of Trump’s agenda are divided over how best to spend their dollars to advance the Trump agenda. Once a whispered concern, the division was out front this week as donors who support President Donald Trump huddled deep in the Texas desert to discuss their strategy.

It’s not that they all oppose the president’s former adviser’s more-radical version of conservatism, though some of them do. Like him, they’re frustrated and angry that the current Republican majorities in Congress have so far failed to rid the nation of “Obamacare,” overhaul the U.S. tax system, build a border wall and more.

But they fear he’ll depose incumbent Republicans in favor of weaker challengers who will then lose to Democrats.

Doug Deason, one of the big donors who attended the private gathering of America First Action, the only Trump-sanctioned super PAC, said that Bannon is wasting time, energy and resources by launching his aggressive campaign to take down Republican lawmakers that he feels stand in Trump’s way.

“I really like Steve. I think he’s a smart guy. He has good intent. I just think it’s kind of like pissing in the wind,” Deason said. “If Steve called and asked for support, I’d say, ‘No, but let’s keep in touch.'”

Tens of millions of dollars are at stake. Already, America First and its allied nonprofit have raised roughly $25 million with another $15 million in “soft commitments” from donors, according to one official who spoke on the condition of anonymity to discuss internal discussions.

Two dozen donors affiliated with America First spent Tuesday at the Mesa Vista, Texas, ranch of billionaire oilman T. Boone Pickens. Many arrived via private jets on the landing strip on the property. The president’s eldest son, Donald Trump Jr., addressed the group, which is also affiliated with Trump loyalists Corey Lewandowski, Katrina Pierson and former Wisconsin Sheriff David Clarke.

Bannon, who left his job as the president’s chief strategist in August, was not invited. He maintains relationships with some America First officials, but he has been focused instead on assembling his own coalition of donors in recent weeks to promote what he recently called “a season of war on the GOP establishment.”

“I think that we are all allies at the end of the day, we all want to see pro-Trump, pro-America-first candidates get elected,” America First spokeswoman Erin Montgomery said. “That doesn’t mean we are going to agree on everything.”

She added, “We really want to be the super PAC that supports the president the best way we can.”

Bannon’s team, however, sees itself less bound to Trump and within its rights to apply political pressure to any and all Republicans.

In fact, Bannon has said he plans to seek Republican challengers for virtually every Republican senator seeking re-election next year, chiefly for the purpose of electing candidates who would remove Mitch McConnell of Kentucky from the post of Senate majority leader.

Bannon has even put reliable Trump agenda supporters, such as Sens. Deb Fischer of Nebraska and John Barrasso of Wyoming, on notice that they aren’t free from close scrutiny.

“We believe the best way to support the president is through a combination of electing more true supporters of his agenda and by putting political pressure on wavering members of the Republican caucus,” said Great America Alliance political strategist Andy Surabian, a close Bannon associate.

It’s “to make them think twice about abandoning the president on key issues,” like taxes, immigration and trade, Surabian added. Such threats work, he said.

Nevada Sen. Dean Heller, who opposed legislation in June to repeal the 2010 Affordable Care Act, co-sponsored new legislation to do so in September after a Las Vegas businessman declared his candidacy to challenge him in the 2018 primary.

Then, this week, Arizona Sen. Jeff Flake, a vocal critic of Trump, announced he would not seek re-election. Flake was being challenged by the Bannon-backed former Arizona state Sen. Kelli Ward.

On Wednesday, Ward’s campaign announced Ed Rollins, chairman of the Bannon-affiliated Great America PAC and veteran GOP strategist, would be chairman of her Senate campaign. The announcement was aimed at seizing on Flake’s announcement in an effort to elevate her standing as a national contender.

Though Trump could seldom contain his contempt for Flake, even the president last week suggested Bannon may be overreaching.

“Some of the people he may be looking at, I’m going to see if we can talk him out of that because, frankly, they are great people,” Trump said at a news conference with McConnell.

One of the key questions donors grappled with in Texas this week was how to navigate around Bannon’s strategy.

The opposition to Bannon’s quest is far stronger among the more establishment-minded Republican campaign committees, which are also amassing millions of dollars to help protect Republican majorities in the House and Senate ahead of next year’s midterm elections. Democrats, buoyed by Trump’s dismal approval ratings, are especially hopeful about the House, where they need to pick up 24 seats to regain the majority.

Spencer Zwick, chief fundraiser for House Speaker Paul Ryan, describes Bannon’s war as little more than a distraction.

“It’s always helpful to have people on the same page. But this idea that Steve Bannon is going to have a dramatic impact one way or another on the midterms, I don’t see that,” Zwick said. “I think frankly tax reform is going to have a bigger impact on these midterms than anything Steve Bannon does.”

Likewise, Republican donor Craig Duchossois, of Chicago, who supports McConnell’s political action committee, is deeply frustrated with the Republican leadership in Congress.

But he says the path forward remains with McConnell and Ryan, not Bannon’s push to promote untested rookies to take down Republican incumbents. His message to Bannon: “Not now, pal.”

Yet roughly a year before the next election, the battle for 2018 campaign cash has only just begun. And the pro-Republican forces start out as divided as ever.

In last month’s special Senate election in Alabama, Bannon worked against the wishes of the GOP establishment, Trump himself and the pro-Trump super PAC to back ex-state Supreme Court Chief Justice Roy Moore, who ultimately won the GOP runoff. Bannon is also promoting anti-establishment candidates in Nevada, Arizona, Mississippi, Wisconsin and New York, and the list is expected to grow.

The pro-Trump America First, by contrast, is more tightly focused on backing candidates Trump supports and those who back his agenda.