Donald Trump escalated his feud with Fox News this week by playing what he believes is his ultimate trump card: blowing them off.

Trump says he's not going to show up for the Republican debate Thursday night because of the scheduled moderator, Megyn Kelly — the longtime Fox News anchor and Kelly File host who has rankled Trump in the past. It's the final GOP showdown before the the Iowa caucuses on Monday, where Trump is surging in the polls but where there are also never guarantees.

Trump's entire campaign has been a series of unlikely antics that beat expectations. So it could be that his seemingly foolish decision to stand up to Fox (and the millions of Republicans who will tune in) could turn out to be another brilliant play in hindsight. Or his decision could be his first big mistake — in the eleventh hour.

The buildup

Trump's back-out was a day-long will-he-won't-he, turning into a drama sure to last right up until Thursday night.

On Tuesday evening, the Associated Press reported Trump "will not be participating" in the Republican debate. Politico elaborated that "plans are instead in the works for a competing event."

Trump tweeted a statement from his campaign:

"Unlike the very stupid, highly incompetent people running our country into the ground, Mr. Trump knows when to walk away. Roger Ailes and FOX News think they can toy with him, but Mr. Trump doesn't play games. There have already been six debates...Mr. Trump has won all of them, in particular the last one. [...] He will not be participating in the FOX News debate and will instead host an event in Iowa to raise money for the Veterans and Wounded Warriors, who have been treated so horribly by our all talk, no action politicians. Like running for office, as an extremely successful person,this takes guts and it is the kind mentality our country needs in order to Make America Great Again."

Trump's campaign manager, Corey Lewandowski, reiterated that Kelly had been openly biased against Trump on air, in a telephone interview with MSNBC's Morning Joe Wednesday.

"You know, what we know is Megyn Kelly is totally obsessed with Mr. Trump," Lewandowski said. "She’s on show after show about why the media shouldn’t be having him on television."

Trump began stirring the pot Tuesday morning in a telephone interview with Good Morning America, when he said he was considering boycotting the debate.

"Well, I’m making a decision," he told ABC Tuesday. "I think she’s not a professional. I don’t think she’s a very talented person. I don’t think she is a good reporter. I think they could do a lot better than that. I love doing the debates. You know, I just do think they should get competent reporters. They shouldn’t use somebody like her. She’s not very good. She’s not very good at what she does, I will tell you that."

He later posted a Twitter poll asking his supporters whether he should skip the debate. The poll had more than 10,000 votes in less than two hours, with responses narrowly favoring Trump to participate. Nevertheless, that evening Trump's campaign announced his decision to boycott the event.

Trump's history with Megyn Kelly

Trump has been in something of a feud with Kelly, whom he publicly accused of doing a terrible job as a moderator, since the first Republican primary debate in August.

Her first question out of the gate at that debate was qualified by some as a tough question and by others as an unserious "gotcha": "Mr. Trump, one of the things people love about you is you speak your mind and you don’t use a politician’s filter. However, that is not without its downsides, in particular, when it comes to women. You’ve called women you don’t like, ‘fat pigs,’ ‘dogs,’ slobs,' and 'disgusting animals.'"

The exchange only went downhill from there, and Trump later made headlines after the debate telling CNN's Don Lemon, "You could see there was blood coming out of her eyes, blood coming out of her wherever."

With Kelly’s return at the debate this Thursday, Trump says he isn’t sure it will be a fair contest.

"Megyn Kelly is really biased against me. She knows that. I know that. Everybody knows that. Do you think she can really be fair at a debate?" Trump said in a video uploaded to his Instagram account on Tuesday.

A video posted by Donald J. Trump (@realdonaldtrump) on Jan 26, 2016 at 10:04am PST

Establishment candidate Jeb Bush, whom Trump has relentlessly mocked as "low energy" throughout the race, jumped into the mix, calling both Trump and President Barack Obama whiners.

.@realDonaldTrump Do you know who else is scared of tough qs from Fox & @megynkelly? Barack Obama. Enough whining. — Jeb Bush (@JebBush) January 26, 2016

Trump also has a weird relationship with Fox News

Trump has history with Fox News, CEO Roger Ailes, and owner Rupert Murdoch (generally). It's all come to something of a head this campaign season.

Before Trump ran for president, he was a frequent call-in guest on many Fox News shows. But once it seemed like he might be a real candidate, Fox, which is something of a standard-bearer for the Republican establishment, started covering Trump more critically.

Kelly's questions, in particular, were widely perceived as part of this effort, like when she asked, "When did you actually become a Republican?"

Trump saw an opportunity, seizing her line of questioning as a good way to start a high-profile feud that most of the media would love.

But Fox News's executives did not. In a November interview with Adweek, Ailes said he has had a "friendly" relationship with Trump for the past 30 years and that he called Trump in the aftermath of the first GOP debate to say, "What the hell is wrong with you? The United States is at war with every goddamn country in the Middle East and you're at war with Megyn Kelly and you think that looks good? It doesn't look good."

Ailes also released a statement in support of Kelly.

Donald Trump's surprise and unprovoked attack on Megyn Kelly during her show last night is as unacceptable as it is disturbing. [...] I could not be more proud of Megyn for her professionalism and class in the face of all of Mr. Trump’s verbal assaults. Her questioning of Mr. Trump at the debate was tough but fair, and I fully support her as she continues to ask the probing and challenging questions that all presidential candidates may find difficult to answer. Donald Trump rarely apologizes, although in this case, he should.

The tit for tat continued through the fall. Trump threatened to cancel all appearances with the news organization last September. (This ban lasted a week.)

.@FoxNews has been treating me very unfairly & I have therefore decided that I won't be doing any more Fox shows for the foreseeable future. — Donald J. Trump (@realDonaldTrump) September 23, 2015

Fox News responded to Trump’s poll Tuesday with a sarcastic statement given to CNN's media reporter Brian Stelter:

We learned from a secret back channel that the Ayatollah and Putin both intend to treat Donald Trump unfairly when they meet with him if he becomes president — a nefarious source tells us that Trump has his own secret plan to replace the Cabinet with his Twitter followers to see if he should even go to those meetings.

But as the no-show threat became more genuine, Fox got more serious. Fox News released a statement on the matter, calling Trump's decision "unprecedented." The network is also accusing Trump's campaign manager of threatening Kelly.

In a call with a Fox News executive, Lewandowski said Kelly had a "rough couple of days after that last debate" and he "would hate to have her go through that again," according to the Fox News statement.

As many of our viewers know, FOX News is hosting a sanctioned debate in Des Moines, Iowa on Thursday night, three days before the first votes of the 2016 election are cast in the Iowa Caucus. Donald Trump is refusing to debate seven of his fellow presidential candidates on stage that night, which is near unprecedented. We’re not sure how Iowans are going to feel about him walking away from them at the last minute, but it should be clear to the American public by now that this is rooted in one thing – Megyn Kelly, whom he has viciously attacked since August and has now spent four days demanding be removed from the debate stage. Capitulating to politicians’ ultimatums about a debate moderator violates all journalistic standards, as do threats, including the one leveled by Trump’s campaign manager Corey Lewandowski toward Megyn Kelly. In a call on Saturday with a FOX News executive, Lewandowski stated that Megyn had a ‘rough couple of days after that last debate’ and he ‘would hate to have her go through that again.’ Lewandowski was warned not to level any more threats, but he continued to do so. We can’t give in to terrorizations toward any of our employees. Trump is still welcome at Thursday night’s debate and will be treated fairly, just as he has been during his 132 appearances on FOX News & FOX Business, but he can’t dictate the moderators or the questions.

Trump responded to the statement on Twitter calling it "nasty" and "dumb."

The statement put out yesterday by @FoxNews was a disgrace to good broadcasting and journalism. Who would ever say something so nasty & dumb — Donald J. Trump (@realDonaldTrump) January 27, 2016

But is Trump serious?

Trump is known for bringing attention to the GOP debates. The first debate, the origin of the Trump-Kelly drama, was the best-rated primary presidential debate in history, with an average 24 million viewers. Trump himself has acknowledged his popularity with the media, telling an Iowa crowd that he doesn’t pay for campaign advertisements because the mainstream media already gives him so much airtime.

"I get good ratings so I can't put commercials," Trump said at a rally in Pella, Iowa. "Can you imagine 15 minutes on Trump, then 15 minutes [on Trump] and commercials that I am paying for in between? I can't do it. People would get sick."

But is Trump serious? As far as Fox News is concerned, his invitation to Thursday's debate is still open.

Go deeper: