(WASHINGTON) — Former President Donald Trump on Sunday called Florida GOP Gov. Ron DeSantis’ endorsement and boosting of moderate Republican Colorado Senate nominee Joe O’Dea, Trump’s political foe, “a big mistake.”

In what may be the first public break amid long-brewing speculation that the two GOP leaders have been privately clashing, Trump paired the statement on his social media platform “Truth Social” with a Washington Examiner article that reported DeSantis, a hardline Republican, recorded a robocall for underdog O’Dea in which he placed full support behind the candidate who has openly sparred with the former president.

“Hello, this is Florida Gov. Ron DeSantis. America needs strong leadership and desperately. That’s why I’m endorsing Joe O’Dea for U.S. Senate. Colorado, please vote for Joe O’Dea,” DeSantis says in the robocall obtained by the Washington Examiner from the O’Dea campaign. “I’ve watched Joe from a distance. And I’m impressed.”

O’Dea, who is trailing incumbent Democratic Sen. Michael Bennet in the polls, said he would “actively” campaign against Trump last week in a CNN interview, if the former president were to run in 2024, in favor of candidates like DeSantis.

Trump retaliated last Monday, calling O’Dea a “RINO” (Republican in name only) and wrote in a statement, “Maga Doesn’t vote for stupid people with big mouths.”

The outcry came as O’Dea was fundraising alongside former President George W. Bush, solidifying a place for him on a small but distinct list of current and former Republicans running in competitive races while speaking out publicly against Trump.

Trump and DeSantis, two GOP champions, have avoided close proximity as the Florida Republican’s national star has risen and speculation that the governor, who was once wholly supported by Trump, might challenge the former president for the Republican presidential nomination in 2024.

Trump has been reported to have criticized DeSantis behind closed doors but had not lashed out publicly until Sunday.

For more from ABC News’ team of reporters embedded in battleground states, watch “Power Trip: Those Seeking Power and Those Who Chase Them” on Hulu, with new episodes on Sunday.

DeSantis has shrugged off questions about whether he is considering a 2024 bid, possibly against Donald Trump — “nice try, man,” he said when pressed about it on “Fox and Friends” in June — though many pollsters have included him in their surveys of future primaries, carving out some favorable odds should he decide to run.

A recent ABC/Ipsos poll found that among Republican registered voters, 72% reported they wanted DeSantis to have either a “great deal” or a “good amount” of influence over the future of the party. Compare that to Donald Trump’s 64%.

While out on the trail, DeSantis has rarely mentioned Trump, who endorsed DeSantis in 2018.

“It’s [DeSantis’] prerogative. I think I would win,” Trump told the New Yorker in June of the prospect of the Florida governor challenging him for the 2024 GOP presidential nomination.

Trump later told Newsmax that he and DeSantis get along well but said he is “very responsible” for the ascending Republican’s success.

Miles Cohen is one of seven ABC News campaign reporters embedded in battleground states across the country. Watch all the twists and turns of covering the midterm elections every Sunday on Hulu’s “Power Trip: Those Seeking Power and Those Who Chase Them” with ABC’s George Stephanopoulos.

Copyright © 2022, ABC Audio. All rights reserved.