Split between Donald Trump and Fox News was one of the US election's biggest surprises

"Et tu, Fox News?" Donald Trump might have reflected as he watched the support of his favourite news network ebb away.

In reality, Mr Trump probably directed something less Shakespearean at the TV screen. Perhaps a shoe.

The split between the White House and Fox has been one of the most unexpected dramas of the 2020 election. Loyal in 2016 and throughout Mr Trump's presidency, the network tempered its support this time.

On election night, in a move that stunned not only the president, it called Arizona for Joe Biden when only 86 per cent of the vote had been counted and Mr Trump was only just behind. Four days later, no other US TV network had called the state.

Mr Trump was reportedly apoplectic. His campaign attacked Fox News "decision desk" director Arnon Mishkin as a "Clinton-voting, Biden-donating Democrat" who made a "terrible decision" and "refused to retract an unjustified call".

The president and his son-in-law Jared Kushner reportedly called Rupert Murdoch, who owns Fox News, But Mr Murdoch, in an email to the Washington Post, said the president himself had not complained. He wrote:  "If he had, I would not have interfered or changed our call."

In the ensuing days, Mr Mishkin was repeatedly brought on air by Fox News anchors and defended the decision. He said: "Arithmetic is more important than politics."

For years, supporters of Mr Trump had chanted "CNN Sucks" at his rallies. But in Phoenix, Arizona, they began chanting "Fox News Sucks"

The network proceeded to step very carefully around the president's allegations of massive vote fraud. In a Friday night broadcast, Fox News anchor Brett Baier said: "We just haven't seen it. It hasn't been presented to us."

Jeffrey McCall, a communications professor at DePauw University, said: "These people have their own journalistic standards that they want to uphold. My guess is that the Murdoch family is not calling into the newsroom to tell Bret Baier how to cover certain kinds of stories."

Reece Peck, the author of called "Fox Populism", said: "Murdoch, at times you can sense him understanding where the political winds are going. Biden is not very threatening to the business community in the United States."

As Americans remained glued to their TV screens, the chaotic news coverage of the election saw several networks cutting away from Mr Trump as he claimed he was being "cheated". A CNN anchor described him as "pathetic".

CNN and Fox News sniped, playing clips of each other and dissecting the coverage, calling into question their rivals' integrity. Meanwhile, Mr Trump claimed that both networks, and MSNBC, will collapse if he is no longer in office.

During his presidency, ratings for Fox News soared and it set a cable news record of 14 million on election night. However, 56.9 million Americans watched election night TV coverage overall, a large drop from 71 million in 2016.

As Saturday, dawned TV networks were left scrambling to explain why they had not yet called the election. Perhaps it was trepidation at the backlash from Mr Trump and his supporters, or uncertainty over how the surge in postal voting would affect prediction models.

Quizzed by his own anchor, CNN political director David Chalian said: "All they do is, every single time vote comes in from one of these states, they plug it into their models and their formulas, trying to ascertain a very high level of confidence."

He suggested it was necessary to be 99.7 per cent sure that "whoever is the number two person in these contests doesn't have a real possibility to overtake the number one person."

Meanwhile, on Fox News even one of Mr Trump's favourite opinion hosts was suggesting he should leave "gracefully" if it came to it.

Laura Ingraham, whom the president watches avidly, said: "If and when it's time to accept an unfavourable outcome in this election – and we hope it never comes – but if and when that does happen, President Trump needs to do it with the same grace and composure he demonstrated at that town hall [on NBC News last month].

"So many people remarked about his tone and presence. Exactly what he needs. And I'm not conceding anything tonight, by the way, but losing, if that's what happens, it's awful. But President Trump's legacy will only become more significant if he focuses on moving the country forward."

She called Mr Trump a "political hero" to tens of millions of Americans who would be the "kingmaker" in 2024.

Mr Trump's reaction is unknown. But it is possible he may have switched over to One America News, a smaller network which is still offering him its full support.