Sound and fury: Donald Trump speaking to the faithful in Wilkes-Barre, Pennsylvania. Credit:AP Trump's blustery Tuesday tweet that "the shackles are off" was a declaration of war on a party, his party, that he seemingly hates more than he does the Democrats. In going all scorched earth, he wants to take down his GOP enemies – some of whom he named early on Tuesday, in a blizzard of angry tweets as he peered from the bottom of a crater that he's dug for himself. It's as though the Republican presidential candidate has put his faltering campaign against Clinton on hold, while he settles scores with Republicans like House speaker Paul Ryan and Arizona senator John McCain. Given what issues from the sewer that passes for Trump's mouth, there were gales of laughter when the worst insult he could hurl at McCain, was that McCain was "very foul-mouthed" –despite Trump's cruel jabs at him, McCain had endorsed Trump up until the "grab them by the pussy" video dropped. And Trump went after Ryan with all guns blazing, accusing him of being worse that Clinton – she being the lowest of the low for many Republicans.

Ardent supporters: Fans cheer for Republican presidential candidate Donald Trump at a rally in Wilkes-Barre, Pennsylvania. Credit:AP These two have never liked or respected each other – one is the polished, quintessential establishment politician, who talks about a need to spend time with his family; the other is a grubby insurgent, who brags about how unsuspecting women find him irresistible - even as he grabs them by the genitals. But Ryan painted a target on his own back on Monday, when his announcement, that he would no longer support or defend Trump, was read as an invitation to all congressional Republicans to stay with, or cut and run from Trump as they saw fit – the objective being to contain what it now appears will be a Republican bloodbath on November 8. Red, white and blue: Supporters of Republican presidential candidate Donald Trump pray during a campaign rally in Panama City, Florida. Credit:AP "Our very weak and ineffective leader, Paul Ryan, had a bad conference call where his members went wild at his disloyalty," Trump shrieked in a tweet. And two hours later: "Disloyal R's are far more difficult than Crooked Hillary. They come at you from all sides. They don't know how to win — I will teach them!"

Interviewed by Bill O'Reilly, one of his Fox News pets, on Tuesday evening, Trump amplified: "I wouldn't want to be in a foxhole with a lot of these people, that I can tell you. ... Especially Ryan" – who he then threatened with the loss of his job if Trump becomes president: "[He] might be in a different position." Supporters of Republican presidential candidate Donald Trump. Credit:AP "They're not giving support - they don't give the kind of support," Trump said, when O'Reilly asked why he was so angry with Republican leadership. "They don't give the support that we really need. Maybe we'll do better without their support. "I don't think I'm that outspoken to be honest with you - I think I've been very nice; I don't think so - look, I went to Ivy League schools. I'm just tired of non-support - and I don't really want support." Darkness descending? Donald Trump, 2016 Republican presidential nominee. Credit:Bloomberg

Why would McCain, a genial GOP grandee who was the party's presidential candidate in 2008; and Ryan, who was the vice-presidential candidate in 2012; stick with a presidential candidate that so many in the Republican establishment consider to be a vile intruder. In a word – fear. Supporters of Donald Trump: Resentment born of inequality can lead to erratic policy. Credit:AP Note that in Ryan's Monday comments, he expressly said that even though he appeared to be going out the backdoor at 100km/hr, it didn't mean that he would not be voting for Trump – again, all that is about minimising the punishment that Trump might inflict on down-ticket candidates. Ditto McCain – his calculus as he faced one of the tightest reelection contests of his career, was that he could not go against Trump if he wanted to hold his Arizona senate seat, in the primary or at the general election.

Republican presidential candidate Donald Trump visits an Eat'n Park restaurant in Moon Township, Pennsylvania. Credit:AP Here are some figures that quantify their fear – Trump's twin tweets of scorn aimed at Ryan on Tuesday each garnered more than 30,000 'likes'. On Monday, one of his sledges at Ryan got more than 75,000; another got more than 44,000. With those figures in mind, Trump surrogate and a predecessor of Ryan's as speaker, Newt Gingrich, urged Trump to double down: "It's time for him to send targeted messages to each district and state and have Republican voters ask their candidates: 'Are you going to help us defeat Hillary Clinton?' And Trump should make it clear that the side effect of not helping Trump is electing Hillary Clinton." That's enough to convey the unprecedented reality that less than four weeks out from the election, the Republican Party is in the grips of a debilitating civil war. For now, desertions by key figures who previously had endorsed Trump have slowed to a trickle – but, truly-ruly, Trump knows what the party establishment thinks of him. And he's a sensitive, thin-skinned soul.

It's difficult to nail what motivates Trump. There's a bully's need for revenge; and also, there's a need to blame others, if as now seems likely; he goes down in a screaming heap on Election Day. But given that even on a good day, Trump can only muster half an idea, it's instructive to look for the source of the other half of the ideas. Early in the Trump campaign, insiders revealed that aides would squabble to be the last to speak to Trump before he stepped out, because all knew that when he spoke he would parrot whatever he was last told. These days that last voice often is his recently appointed campaign CEO, Steve Bannon, previously the chairman of the far-right news website Breitbart – which is funded in part by one of Trump's most generous donors, the money-bags, father and daughter team of Robert and Rebekah Mercer, who reportedly were instrumental in installing Bannon at the top of the Trump machine.

Steeped in rightwing conspiracy theories, Bannon has long considered Ryan to be Public Enemy No. 1. At Breitbart, his mission was to destroy Ryan, who he sees as the ring leader in an elite globalist clique bent on doing down the US through global trade deals and increased immigration. Bannon dubbed Breitbart as "Trump Central," and he was so shameless in skewing its reporting to root for Trump that as early as August 2015, he declared in an email to a colleague – "I'm Trump's campaign manager."

We're indebted to The Daily Beast and The Hill for acquiring a bundle of internal Breitbart emails that shed light on Bannon's thinking and motivation – and therefore Trump's. On Ryan's appointment as speaker in December 2015, Bannon began referring to him as "the enemy," declaring that the "long game" for his news site was to ensure that Ryan was "gone" within months. "But it's not just Ryan," a Breitbart source told The Hill as he explained Bannon's worldview. "Every institution in American politics has been exposed as fraudulent and working against the American people. "Trump is running against the evil empire," the source said of Bannon's thinking. "The entire machine stands against him, and Paul Ryan is the face of the evil empire. But so is Hillary Clinton and so are her allies throughout the mainstream media." Under Bannon's command, a Breitbart report accused Ryan of hypocrisy because he had a "border wall" around his Wisconsin home but he rejected Trump's proposal for a wall on the Mexico border; and another levelled the same charge, based on Ryan sending his children to a Catholic school that had a religious admission test while at the same time opposing Trump's call for a religious test for Muslims entering the US.

"He's an instrument of destruction," Ben Shapiro, a former Breitbart staffer, told The Hill. "Bannon's always wanted to burn everything down…and any chance he has to wriggle this into a way to destroy Paul Ryan, he'll absolutely do it." As he beat his chest on Tuesday, Trump acknowledged that with his new campaign team headed by Bannon, he felt emboldened, because no longer was he required to restrain himself to please the Republican establishment. So now we have Trump's Twitter sprays at Republicans; and at his otherworldly rallies, at which he is introduced as "the next president," Trump criticises them along with Clinton, as he pitched to the fervent believers who are his base. But mesmerised as Trump is by the adoring crowds, his support is sliding in wider America. Evangelical Christian leaders who previously endorsed him are walking away – Andy Crouch, the executive editor of the evangelical publication Christianity Today, wrote in an editorial published Monday: "Enthusiasm for a candidate like Trump gives our neighbours ample reason to doubt that we believe Jesus is Lord.

"They see that some of us are so self-interested, and so self-protective, that we will ally ourselves with someone who violates all that is sacred to us — in hope, almost certainly a vain hope given his mendacity and record of betrayal, that his rule will save us." And women, probably the single most important demographic in the campaign, are leaving Trump in droves. A poll published Tuesday by The Atlantic had Clinton ahead among all voters by 11 percentage points – in the same poll two weeks ago, Clinton and Trump were tied. And among independent voters, Trump and Clinton's positions were reversed – last week, he led by eight points; this week, Clinton has raced ahead, and now is in front by a margin of 11 percentage points. But the data on women, collected in the days before and after the "grab them by the pussy" bombshell, is even scarier for Trump – with women generally, Clinton is ahead by 33 percentage points; and in just a week, support for Trump from likely women voters has dropped five points – to 28. It get's worse. Married women who had not attended college previously were bedrock for Trump. But in The Atlantic poll they now break evenly between Trump and Clinton. In 2004, George W Bush won their support by 19 points; in 2008, McCain by 17 points; in 2012, Romney by 20.

One of the best insights into the emotional and political contortions of GOP congressional members as they attempt to balance their disgust at Trump with their calculations on the political cost of disowning him, is an open letter published on Monday by Mark Amodei, who also is Trump's campaign chief in Nevada. Sticking with Trump, he seeks political cover in claiming that he'll do what a good Democrat would do: "I choose not to tear my party of choice apart because Donald Trump said and did some frankly awful things in his past. It is worth noting that during some dark days in Secretary Clinton's past, her party has closed ranks and defended their nominee … I will follow my Democrat colleagues' example, and not cannibalise my nominee because he has said and done some regrettable things." But Amodei also worries about what his family – particularly his sister and two daughters, who he says are "understandably sceptical" – make of his position and of Trump: "They are all intelligent, independent and critical thinking women. … Mr Trump, you have your work cut out for you with them in the next 30 days, to convince them that you are the leader they can be proud of. Call me and I'll give you their phone numbers." Most Republicans know Bill Kristol, editor of conservative The Weekly Standard, as one of that helpful talent scouting team that brought them Sarah Palin as a vice-presidential candidate in 2008; and before that, as a talking head for the discredited but influential neoconservative movement during the George W Bush years.

Loading These days Kristol has a new calling – warning of Armageddon. On Monday, he tweeted: "We've never seen a meltdown like Trump's in a presidential election. Republicans sticking with Trump have no idea how bad things could get."