Heather Nauert's promotion shows the extent of Fox News's influence on the White House

Heather Nauert’s promotion to America’s UN ambassador will solidify one of the more notable trends in Donald Trump’s presidency - the remarkable influence of Fox News. 

Ms Nauert, who takes up the role from after being top spinner at the US State Department, spent more than a decade at the right-leaning cable news channel before hopping into government two years ago. 

Her lack of top level diplomatic experience has left critics seething, questioning whether she really has the credentials to replace Nikki Haley at the UN top table in New York, where she will be expected to faced down America’s foes and lobby to pass crucial resolutions. 

But the big brand on her CV - Fox News - is one that Mr Trump has proved especially drawn to since he entered the Oval Office, not least in his top hires. 

Earlier this year, John Bolton, the mustachioed foreign policy hawk and a former US ambassador to the UN himself, was picked for the position of White House national security adviser despite his ties to former president George W Bush, usually a negative point for Mr Trump. 

His repeated appearances on Fox News, banging the drum for a hard line on Iran and North Korea, was said to have caught Mr Trump’s eye - a marked contrast to the formal military style of HR McMaster, the man who held the role at the time. 

(Mr Trump would get bored during briefings from Mr McMaster and once mocked his dress sense, according to Bob Woodward’s book Fear, which quotes the president saying his cheap suits made him look “like a beer salesman”.)

Two months later Mr Trump appointed another Fox name to his inner circle -  Bill Shine, a former executive at the broadcaster with two decades of experience there.  

Mr Shine was given the title of White House director of communications and is known to have played a hand in the staging of many of Mr Trump’s set-piece interviews since joining. 

It is not just appointments where the influence of Fox News can be seen. Mr Trump enjoys a close relationship with many of the channel’s top stars. 

Sean Hannity, whose evening show often is the highest rating on cable news, is an arch supporter of the president and enjoys access few other media figures can rival. 

Mr Hannity and Mr Trump frequently share late-night phone calls, usually after his 9pm programme has aired, where they chat through the latest developments making the headlines, according to a deep dive into their relationship published by New York Magazine. 

It is Mr Hannity who often gets the Trump interviews. Mr Trump in turn is known to urge his 50 million-plus followers on Twitter to tune into his ally’s show. 

And in the final days of the November midterm elections campaign Mr Hannity even appeared on stage at one of the president’s rallies, prompting a rare public rebuke from his employers. 

In fact it is Fox - whose editorial line chimes with Mr Trump, not least on demands for a harder stance on immigration and law enforcement - that almost always gets the interviews. 

CBS’s White House correspondent keeps a tally of the numbers. Last month, he noted that Mr Trump had given 40 interviews to Fox as president. That compared to four for CBS, three for ABC and zero for CNN. 

But the channel’s influence spreads wider than that. Mr Trump, who records cable news shows and watches them back via his TiVo box, is an avid consumer of the channel’s output. 

One of his favourite programmes is Fox & Friends, the breakfast show. Another is Lou Dobbs Tonight, a nightly prgoramme on Fox Business. 

Mr Trump will tweets quotations from these shows wholesale, using the quotation marks to hammer home points he appears to endorse without directly putting them in his own name. 

Often, the remarks of Fox News talking heads appear to directly lead to the president taking some form of action. 

Back in January, Congress was due to sign-off a bill renewing surveillance powers for intelligence agencies. Bipartisan support had been secured, with the White House backign the bill. 

Then, on the day of the vote, Mr Trump unexpectedly tweeted that the act “may have been used, with the help of the discredited and phony dossier, to so badly surveil and abuse the Trump Campaign”. 

It caught the Republicans on Capitol Hill totally off guard. Why was the US president suddenly lashing out against a piece of legislation he was meant to be backing? 

Soon an explanation was found. Forty seven minutes earlier a talking head said on Fox & Friends: “I don't understand why Donald Trump is in favor of this. His woes began with unlawful foreign surveillance and unconstitutional domestic surveillance of him...”

It took a phone call from Paul Ryan, the Republican leader in the House of Representatives, which reportedly lasted 30 minutes for the president to eventually relent. 

He tweeted somewhat sheepishly two hours later: “With that being said, I have personally directed the fix to the unmasking process since taking office and today’s vote is about foreign surveillance of foreign bad guys on foreign land. We need it! Get smart!”

Another example came in March during negotiations for government spending - something decided by Congress but ultimately approved by the White House. 

After weeks of wrangling, a $1.3 trillion spending bill was passed by Congress (both parts of which were controlled by Republicans at the time.) Mr Trump was expected to sign it into law. 

But the lack of funding for his Mexico border wall - just $1.9 billion had been set aside, well short of the $25 billion being sought - left Fox News hosts fuming. 

Laura Ingraham, who has her own show on the channel, called it a “legislative scam”. Ann Coulter, another leading conservative name and regular Fox guest, warned the president he would be impeached if he followed through. 

In the face of the conservative onslaught, Mr Trump announced he was considering vetoing the legislation. He eventually relented, but the his sensitivity to the criticism was plain to see.

So why the closeness with Fox News? The president’s admiration for its Australian owner Rupert Murdoch is one possible explanation. Michael Wolff’s book Fire and Fury details how Mr Trump sees him as one of the last great media titans and was hurt by his lack of interest before he ran for the White House. 

Another is the overlap in agenda. Many of the touchstones of Mr Trump’s presidency are championed by the news channel. His presidency gets a sympathetic showing. 

A third is its audience. Fox viewers are Trump voters. The channel contributed to his unprecedented rise from reality TV star and business mogul to president. 

To keep his supporters on side, and to remain in tune the conservative movement he attached himself to with such success, Mr Trump turns to Fox News. 

When Ms Nauert takes her seat at the top UN table, America’s voice will be that of a Fox News correspondent with just two years’ diplomatic experience - and the mindmeld becomes that bit more pronounced.