There is no precise, scientific means of explaining what determines elections, opinion polls or betting markets. Each election and each candidate is unique, and even the individual voter cannot reliably explain why they react in a certain way.

My belief, held pretty much throughout my adult life based on the experience in England, is that the number one factor is media. Not necessarily editorial bias (although that matters) but narrative created over both long and short-term.

Historically, that has meant that any serious candidate has to win over the mainstream media – in particular TV. Yet this presidential cycle has been so different that many are beginning to disagree. Now it’s all about Twitter, social media and maybe a few friendly outlets that will do your bidding. Donald Trump proves that. I’m pretty sure he thinks so too, as it would explain a lot.

I disagree and think events over the past few days will destroy his bid. Going to war with the media is never a good move. They helped create him and, now he’s pushed them too far, they’ll destroy him.

Back at the start, they thrived on his every word. Or more likely, tweet. In the bizarre, 17 runner horse race that was the GOP primary, his celebrity and headline-grabbing knack of political incorrectness drove previously unimaginable ratings.

By appealing to enough, if not a majority of the GOP base, he sucked up all the media oxygen. Jeb Bush, the only comparably recognisable name, was the perfect establishment target to bully. It was great entertainment.

Whilst the other 15 jockeyed for position, he opened up a commanding lead. By the time they’d whittled down to a manageable number of rivals, capable of being heard whilst scrutinising Trump’s dubious credentials, it was too late.

With the nomination secure, Trump had the floor to himself and set about running the most inept campaign in history, with one gaffe after another. The election became a referendum on an ill-qualified, offensive candidate and the media spotlight merely served to exacerbate his toxicity with a majority of voters.

Consequently without doing anything to enthuse the country or deal with her own fundamental weaknesses, Hillary Clinton became the president-elect, well clear in the polls.

However with that came scrutiny and the moment Trump managed to avoid controversy for a couple of weeks, the gaping holes in Clinton’s case became clear. Hence her recent catastrophic news cycle. Once again, the polls responded to the news cycle and this week Trump erased her longstanding lead.

Now the media had the toss-up contest they craved, the trend begun to flip back. I’ve felt the news cycle was turning against Trump for days – scrutiny into his lack of transparency on health and more importantly, business affairs and tax returns. Then finally yesterday, Trump’s past caught up with him.

It has been something of a mystery how Trump has gone through this entire cycle without anyone pinning him down over the infamous birther theory. Whatever his surrogates or fanatical supporters say, 99% of humanity associates birtherism with Trump. He popularised this conspiracy theory and led the charge.

It isn’t just liberals who see it that way. Less than a year ago, he threw the same attack at Ted Cruz and retweeted this about Cruz and his other main GOP rival Marco Rubio.

 

"@ResisTyr: Mr.Trump…BOTH Cruz AND Rubio are ineligible to be POTUS! It's a SLAM DUNK CASE!! Check it! https://t.co/NjqWP0pP6X"

— Donald J. Trump (@realDonaldTrump) February 20, 2016

 

There are legions of tweets and TV interviews to prove it, many of which are now doing the rounds. Trying to blame birtherism on Clinton – relentlessly debunked – will only wash with the most on-message Trump supporter. An e-mail from a low grade, anonymous operative is no more Clinton’s responsibility than the picture of Melania that caused such trouble after Wisconsin was the personal responsibility of Cruz.

This line is not going to convince open-minded swing or undecided voters. As with Trump’s revenge attack on Heidi Cruz, persisting with it will only keep the issue alive and rebound on him.

Birtherism alone is not going to determine the election but Trump’s response to the scrutiny may do so. This could have been a straightforward apology and acceptance that he made a mistake. Job done and everyone moves on to more serious issues. This was a brief window when Trump could have pivoted and even tried to claim the centre ground, appearing presidential. It has closed.

Instead, by building a media frenzy, using them for free airtime and then completely failing to deliver, Trump could not have played it any worse. His 34 second, unapologetic statement, merely acknowledging Obama was born in the States, blaming Clinton and refusing to take questions, has made enemies of the overwhelming majority of journalists. The 25 minutes free air-time of veterans endorsing him is a small gain at a potentially massive cost.

This is now about more than politics. Nobody likes being played and they can see how a President Trump would treat the media and the general idea of scrutiny. The furious language and headlines being thrown around by largely neutral organisations – liar, conspiracy theorist, racist, conman – is not business as usual. Even if journalists thought that, they were mostly biting their tongues.

For sure, Trumpians will claim CNN, NBC and the Washington Post are systemically biased against their man. That’s their perspective. I disagree, having watched and read endless scrutiny into Clinton’s e-mails and foundation on those outlets. They’re as imperfect as the BBC, but they try and scrutinise both sides and let them have an equal say.

There’s been a lot of media handwringing about what Trump has been allowed to get away with in the past. Bullying Megyn Kelly and walking away from the Iowa GOP debate. Not raising this explosive birther issue in numerous debates, town halls or interview opportuntities. Failing to meet the same transparency standard as all recent presidential candidates on health and tax. Making pledges on that front, then not delivering.

I think all that changes from now. The media no longer need Trump to drive ratings – at this stage of the cycle, intense public interest is a given. Going after him would be just as good for ratings.

Trump clearly believes he doesn’t need them. That a coalition of Fox News (which isn’t totally beyond criticising him, if nonetheless predictably one-sided), Breitbart and the internet can propel him to the presidency. I don’t buy it. There aren’t enough undecided voters in that pool and anyway, plenty of conservatives are disgusted by birtherism.

Moreover, those one-sided outlets rarely shape the overarching media narrative. If they did, Democrats wouldn’t have won four of the last six presidential elections, and the popular vote in a fifth.

It’s interesting to see John Kasich doing media interviews this week, trying to forge common ground with Obama over trade. As soon as I started doing US media I said he was the most electable GOP candidate and remain convinced that he would have won a landslide against Clinton.

Kasich is the definition of the candidate the middle ground (that decide elections) desires. A pragmatic politician who doesn’t trade in personal insults and can reach across the aisle. The Governor of Ohio says he almost certainly won’t vote for Trump. I wonder if that non-endorsement alone has a negative effect in a state he absolutely must win.

I’ve never wavered from my belief that Clinton would win but there’s no denying the previous week had been a disaster for her. Now it feels like ancient history. I reckon we’ll once again see this changing media narrative affect the polls, Clinton restore her lead and talk of a landslide resume.