Conservative media stars are bucking GOP leadership and endorsing an opponent of a vulnerable Republican senator

Top conservative media figures have increasingly lined up against one of the most vocal critics of President Donald Trump in the Senate.

Since the beginning of Trump’s presidential campaign in 2015, Sen. Jeff Flake of Arizona has consistently criticised his rhetoric and policy positions on issues like immigration.

He called for Trump to drop out following the Access Hollywood tape that leaked in October, and he released a book that was largely seen as a rebuke of Trump’s ideology and style of governance.

Now, Flake’s Senate seat is under threat and Trump’s boosters are trying to help get the embattled senator’s primary opponent elected in his place.

On his radio show on Wednesday, Fox News host Sean Hannity endorsed Kelli Ward, a former state senator who is challenging Flake from the right.

“I cannot any longer support weak Republicans,” Hannity said. “I will not support people who break their promises, I will not support people who don’t keep their their word.”

Hannity was the second right-wing figure this week to throw their weight behind Ward, whom he said “welcomed the president to the state, unlike [Sen. John] McCain and Flake.”

On her radio show on Tuesday, Laura Ingraham, the conservative radio host who is rumoured to be in talks for a primetime show at Fox News, also endorsed Ward.

Two endorsements on syndicated conservative talk radio aren’t likely to have a huge impact on an election almost a year away, but they are a marked shift in the far-right’s willingness to publicly challenge figures who are supported by Senate leaders like Majority Leader Mitch McConnell and the chair of the National Republican Senatorial Committee Cory Gardner, both of whom have publicly backed Flake.

The endorsements are the most high-profile that Ward has received since seeking higher office.

When Ward challenged McCain last year, she received almost no major national endorsements aside from Mississippi state Sen. Chris McDaniel, who lost the 2014 Mississippi GOP primary to Sen. Thad Cochran (Hannity hosted Ward on his radio program last year, but didn’t explicitly call for McCain’s ouster).

Trump himself has very publicly flirted with crossing McConnell to target Flake, meeting with several other potential Republican primary challengers backstage at his Arizona rally on Tuesday. And last week, he said he supported Ward’s entrance into the race.

Trump previously promised to spend as much as $US10 million against Flake, and top Republican donor Robert Mercer donated $US300,000 to a pro-Ward super PAC.

In recent weeks, Trump has also repeatedly blasted Flake on Twitter.

“Phoenix crowd last night was amazing – a packed house,” Trump tweeted. “I love the Great State of Arizona. Not a fan of Jeff Flake, weak on crime & border!”

Ward has embraced the support, running a campaign highly critical of Flake’s denunciation of Trump.

On Hannity’s show on Wednesday, Ward described Flake as a “pretty weak senator,” and said it was “amazing” to see Trump’s criticism of Flake.

“Jeff Flake and John McCain insult Republican voters again, and again, and again, because they tell us what they say we should think,” Ward said. “I think times are changing. I think Donald Trump’s election to be president of the United States was like storming the beach at Normandy.”

Flake has already attempted to cast Ward as a right-wing fringe candidate.

In an ad released earlier this week, Flake cast Ward as a conspiracy theorist, releasing an ad dubbing Ward “chemtrail Kelly,” a reference to a town-hall she organised to discuss the “chemtrail” theory, an anti-government conspiracy that speculates that the federal government using jets to spray chemicals on citizens.