In March, as Gov. Ron DeSantis of Florida laid the groundwork for his presidential run, he joined the Fox News host Brian Kilmeade to play a nationally televised game of catch on his hometown baseball field outside Tampa.
The questions Mr. DeSantis faced were as relaxed as the tosses.
“Locker room gets you ready for the press, right?” Mr. Kilmeade asked. “Because your teammates, if they like you a lot, they rip you all the time.”
At the time, Mr. DeSantis was seen by many in the Republican Party as the strongest possible alternative to former President Donald J. Trump, who had repeatedly attacked the network and had seen his relationship with its owner, Rupert Murdoch, evaporate.
Four months later, with Mr. DeSantis’s campaign having failed to immediately catch fire against Mr. Trump, Fox News is not taking it quite so easy on Mr. DeSantis anymore.
Over the last week, he has confronted noticeably tougher questions in interviews with two of the network’s hosts, Will Cain and Maria Bartiromo, who pressed him on his anemic poll numbers and early campaign struggles. It was a striking shift for a network that for years has offered Mr. DeSantis a safe space as a congressman and a governor.
Other outlets in Mr. Murdoch’s media empire have also been slightly less friendly of late.
A recent editorial in The Wall Street Journal criticized a tough immigration bill that Mr. DeSantis signed into law in May. And The New York Post, which hailed the governor as “DeFuture” on its front page last year, has covered his lagging poll numbers, as well as the backlash to a video his campaign shared that was condemned as homophobic.
Mr. DeSantis was always bound to be subjected to more scrutiny as a candidate, rather than a candidate in waiting. His decision to challenge Mr. Trump — who remains a favorite of Fox News’s audience and some of its hosts, including Ms. Bartiromo — was also certain to result in sideswipes from fellow Republicans.
But taken together, the signs of skepticism from previously friendly conservative megaphones suggest that Mr. Murdoch’s media empire might now be reassessing him as the early shine comes off his campaign.
Even if Mr. Murdoch’s outlets as a whole are less determinative of outcomes in Republican politics than they once were, they remain influential, and G.O.P. candidates and major party donors still pay close attention to their coverage.
Whether Mr. Murdoch wants to see Mr. DeSantis as the nominee is unclear. Some of Mr. DeSantis’s moves — like his ongoing punitive battle with Disney — are unlikely to have pleased the business-minded Mr. Murdoch, who nearly a decade ago called for federal officials to make immigration reform a priority.
The media mogul likes to watch political races play out, even live-tweeting reactions to one of the Republican presidential debates during the 2016 election. Mr. Murdoch has privately told people that he would still like to see Gov. Glenn Youngkin of Virginia enter the race, according to a person with knowledge of the remarks. And he has made clear in private discussions over the last two years that he thinks Mr. Trump, despite his popularity with Fox News viewers, is unhealthy for the Republican Party.
A spokesman for Mr. Murdoch and a spokesman for Fox did not respond to an email seeking comment.
Mr. DeSantis’s campaign declined to comment. Privately, his advisers say that tougher questions were always expected and that the governor plans to continue holding interviews with Fox hosts who may challenge him.
Republican voters view Mr. DeSantis favorably overall, but he has been unable to meaningfully narrow the polling gap between him and Mr. Trump since entering the race, even as he remains the former president’s leading challenger. Mr. DeSantis has also continued to show an awkward side in unscripted exchanges where he is challenged — a contrast with Mr. Trump, a no-holds barred campaigner who seems to enjoy combative interviews.
The tide has not completely shifted. On Monday, The Wall Street Journal’s editorial page took a new jab at Mr. Trump for adjusting his policy positions depending on which audience he is addressing, and gave Mr. DeSantis a slight boost by comparing him favorably.
For Fox, navigating its coverage of Mr. DeSantis, Mr. Trump and an already bitter Republican presidential primary race is just one challenge.
This spring, the network paid dearly for its airing of Mr. Trump’s false election claims, settling a defamation lawsuit related to its coverage of the 2020 presidential contest for a staggering $787.5 million. Further legal dangers lie ahead.
Less than a week after the settlement, Fox dismissed Tucker Carlson, its most popular prime-time host, in an earthquake for the conservative media ecosystem. The network now faces persistent concerns about dipping ratings and upstart competitors that are eager to claw away Fox viewers who want a more pro-Trump viewpoint.
Although Mr. Trump still appears on Fox News, his relationship with the network remains hostile, to the extent that people close to him say there is little chance he will participate in the first Republican presidential debate, which Fox News is hosting next month. (Mr. Trump, who leads in national polls by roughly 30 percentage points, also does not want to give his rivals a chance to attack him in person, those people said.)
Mr. DeSantis, who typically shuns one-on-one interviews with mainstream political reporters, has a long and positive history with Fox News.
As a congressman, he co-hosted the show “Outnumbered” several times. In 2018, he announced his run for governor on “Fox & Friends.” During the coronavirus pandemic, Sean Hannity of Fox News praised Mr. DeSantis in an interview, saying: “I’m an idiot. I should be in Florida. You should be my governor.”
And after declaring his candidacy for president in a glitch-ridden livestream on Twitter seven weeks ago, Mr. DeSantis immediately went on Fox for an interview, although the network did poke fun at his technical difficulties.
Mr. Trump himself raged earlier in the year about what he perceived as Fox’s excessively friendly treatment of Mr. DeSantis. “Just watching Fox News. They are sooo bad,” Mr. Trump wrote on his TruthSocial site in May. “They are desperately pushing DeSanctimonious who, regardless, is dropping like a rock.”
He has also taken digs at features in The New York Post, including one in which the writer Salena Zito did a lengthy interview with Mr. DeSantis in his hometown, Dunedin, Fla. — an article Mr. Trump denounced as a “puff piece.” (The Post, once one of Mr. Trump’s favorite papers, has ripped into him.)
Mr. Trump was undoubtedly more pleased last Thursday when Mr. Cain, the Fox host, pressed Mr. DeSantis on his poll numbers, asking the governor why he was so far behind.
In response, Mr. DeSantis suggested that he was being unfairly attacked both by the “corporate media” and, somewhat incongruously, by the president of Mexico, Andrés Manuel López Obrador, who has criticized him for his hard-line stances on immigration.
“So I think if you look at all these people that are responsible for a lot of the ills in our society, they’re targeting me as the person they don’t want to see as the candidate,” explained Mr. DeSantis, adding that his campaign had “just started.”
Mr. Cain tried again, saying that he believed Mr. DeSantis had “done a wonderful job” as governor but that “there are those that say there’s something about you that’s not connecting, for whatever reason, not connecting with the voter.”
Mr. DeSantis wove around the question and noted that his campaign had raised $20 million in its first six weeks.
“We’re in the process of building out a great organization, and I think we’re going to be on the ground in all these early states,” he said.
Mr. Cain is no dyed-in-the-wool Trump supporter. He has talked about voting against Mr. Trump in 2016. But when Mr. DeSantis joined Ms. Bartiromo, who relentlessly pushed the former president’s conspiracy theories about the 2020 election, for an interview on Sunday, he surely expected to be challenged.
“You’ve done a great job pushing back against ‘woke,’ we know that,” Ms. Bartiromo said after allowing Mr. DeSantis to hit his usual talking points for several minutes. “But I’m wondering what’s going on with your campaign. There was a lot of optimism about you running for president earlier in the year.”
Mr. DeSantis forced out a laugh as Ms. Bartiromo read negative headlines about his campaign. He then jumped into a rebuttal that focused on his efforts to build strong organizing operations in Iowa and New Hampshire.
“Maria, these are narratives,” he said. “The media does not want me to be the nominee.”
Jonathan Swan contributed reporting from Washington.