(Bloomberg) – Oil industry leaders contributed top dollar to President Donald Trump in 2020. But now oil and gas titans are underwriting his GOP rivals instead.

Florida Governor Ron DeSantis and former U.S. Ambassador to the United Nations Nikki Haley were the biggest beneficiaries of donations from oil and gas representatives in the third quarter, according to a Bloomberg review of new campaign finance disclosures filed with the Federal Election Commission. Both Republicans have done fundraising tours through the oil patch, with DeSantis unveiling his energy policy platform in front of a drilling rig in Midland last month.

And while some notable leaders have cut checks to Trump’s main presidential campaign committee — including Continental Resources Corp. founder Harold Hamm and offshore supply veteran Larry Rigdon — others are steering clear.

Take, for instance, Jeff Hildebrand, Chief Executive Officer of Hilcorp Energy Co., and his wife Melinda Hildebrand, who have showered much of the Republican field with cash this year. Together, they sent $3,300 to North Dakota Governor Doug Burgum, $3,300 to Haley, $3,300 to DeSantis, and, in late July, $6,600 to former Vice President Mike Pence and $3,300 to South Carolina Senator Tim Scott, disclosures show.

In the White House, Trump was an enthusiastic supporter of the oil and gas industry, who championed domestic production and stripped away federal regulations he said were standing in the way. But Trump’s unpredictability — for instance issuing surprise decrees blocking offshore oil leasing near the southeastern US in the weeks before the 2020 election — poses a hefty challenge to energy companies making investment decisions that can take decades to pay off. Candidates vying for the Republican presidential nomination endorse broadly similar energy and environmental policies.

While contributions are lopsided now, donors generally coalesce behind nominees once they are chosen or appear to be a lock. In the third quarter, DeSantis and Haley outraised other GOP presidential candidates, based on a sampling of oil industry and Permian-focused donors.

Donations to presidential campaign committees are capped at $3,300 per candidate per election — or $6,600 for both the primary and the general contest.

Here’s a breakdown of some notable industry donations this year.

Nikki Haley. Haley has picked up financial support from a swath of oil executives with ties to the prolific Permian basin that stretches across the Texas-New Mexico border. That includes $6,600 from Syed Javaid Anwar, the founder and Chief Executive Officer of Midland Energy Inc., and $3,300 from Ben “Bud” Brigham, who founded a string of exploration companies and oilfield logistics provider Atlas Energy Solutions.

Executives of Pioneer Natural Resources Co. — the Permian powerhouse Exxon Mobil Corp. is buying for $60 billion — also have sent money to Haley, with $3,300 each from president Rich Dealy and Executive Vice President Mark Berg, as well as $6,600 from CEO Scott Sheffield in the second quarter. Sheffield’s son, Bryan Sheffield, the founder of Parsley Energy Inc., and his wife, Sharoll Sheffield, together donated $13,200.

Enterprise Products Partners leaders also threw their support behind Haley, with co-CEO Jim Teague giving $6,600 in March and co-CEO Randy Fowler contributing $3,300 in September.

Other notable Haley donors:

Tucker Bridwell, an oil industry veteran and former board member for Concho Resources Inc., Ram Energy Resources Inc., Petrohawk Energy Corp., and other firms, $6,600

Richard Kinder, chairman of Kinder Morgan Inc., and his wife Nancy Kinder, $6,600

Trevor Rees-Jones, president of Chief Oil & Gas LLC and founder of Rees-Jones Oil & Minerals, $6,600

Ray Hunt with Hunt Oil Co., $6,600

Hunter Hunt with Hunt Consolidated Inc., $6,600

Ron DeSantis. DeSantis wooed prominent Texans in September and has garnered oil patch donations, including $3,300 each from Allan Bloxsom, President of Fort Apache Energy Inc.; Jonathan Barrett, chairman of the board of Battalion Oil Corp.; and Ken Waits, CEO of Mewbourne Oil Co.

Kelcy Warren, the chairman of pipeline operator Energy Transfer LP, and his wife Amy Warren together contributed $13,200. By contrast, in 2020, Kelcy Warren backed Trump by giving $10 million to America First Action, a super political action committee, and $1 million to Trump Victory, which divided money between the former president’s campaign, the Republican National Committee and state parties. At the time, Amy Warren sent $1.1 million to Trump Victory. Super PACs, which work independently of campaigns, can accept unlimited donations.

Other notable DeSantis donors:

Canary LLC CEO Dan Eberhart gave $6,600, while his brother Jacob Eberhart and sister-in-law Kelli Eberhart each contributed $3,300 during the third quarter.

Alan Smith, CEO, Rockcliff Energy, $1,000

John Garrett with Fair Oil Co., $3,300

Donald Trump. One of Trump’s biggest oil industry supporters historically has been Hamm, the billionaire and Continental Resources founder who’s donated $769,400 to Trump Victory since 2016. Hamm also played an unofficial role as an energy adviser to Trump on the campaign trail in 2016 and spoke at the 2016 Republican National Convention.

But earlier this year, Hamm was instead contributing to other Republican contenders — with DeSantis and Haley each receiving $6,600. Hamm said he didn’t believe Trump could win the White House in 2024.

Hamm pivoted on Aug. 22, when he sent $3,300 to Trump’s campaign. Asked about the contribution, spokeswoman Kristin Thomas said only that “Mr. Hamm has consistently said that he will support anyone he believes will make a good president.”