She is already campaigning against him as though he had the nomination, and every attack on his statements strengthens his claim to be the outsider the Democrats fear. Is her strategy to give Trump a helping hand, because she figures that she can easily beat him?

Don't bet on it. Trump may seem to be following a crazy and dangerous strategy, of playing the populist among the discontented white American working class in a way that might seem calculated to lose him votes everywhere else. But he is also a cunning and clever campaigner, who is seeing off most of the mainstream Republican candidates, even as he has appalled mainstream opinion, the rest of the world, and the broad political establishment. Clinton ought to be able to beat him, and herself looks at this stage unbeatable for the Democrat nomination.

But she too is given to stumbling, not least when confronted with scattergun slurs from people such as Trump. She has struggled to mobilise enthusiasm among supporters, even as the person who might rescue America from Trump. If she wins, she may well cause the disintegration of the Republican Party. If she muffs it, as well she may, heaven help us all. Especially in places such as Australia which, as President Barack Obama remarked this week, is given to seeing craven loyalty to the US as the first and the last thing.

The tricky thing is that the tactics of a Trump could work against Hillary Clinton in a way that might not work against a worthy, but more pedestrian, Democrat nominee. (Not Bernie Sanders, however decent, because he is slightly to the left of George Brandis and is thus, in the US, unelectable as an out-and-out socialist.) Rightly or wrongly, Clinton (if anything Hillary more than Bill) inspires visceral rage in the nutty end of the Republican Party. Organising against her would be a work of passion and delight, not a brave duty. A demagogue rather than a professor is just the person to take her on.

No one would be more disappointed if Trump got the nod at the primaries than the Republican National Committee. But to many voters, that's the point of the thing. Ted Cruz, who vies with Trump for the same constituency by (likewise) pretending to be an outsider to politics would also be a Republican nightmare, but not as bad.

The Republican establishment has struggled to convince a good part of its base that Trump is unelectable and, could well lead the party, and perhaps America, over a cliff. When, at one stage, that establishment "knew" that Trump would eventually fade away, it worked hard to extract from him commitments that he would not lead a third-party challenge against the official Republican candidate. It got, it sort of, though I wouldn't trust him.

But now there is talk that Trump himself needs guarantees that the Republican establishment will not itself lead a revolt (or not play completely dead) if Trump garners the nomination. There are some who would rather a President Hillary Clinton, Democrat, to a populist, nativist and bizarre Trump.

That's not merely a matter of the Trump personality and his indifference to the party's old cliques and methods – on umbrella philosophy. It's also a reflection of a judgment that if Trump gets the nomination, it means that the party has been captured by zealots, populists and extreme conservatives and is beyond saving as any sort of electable conventional right-of-centre political formation. And that he could do serious damage to the nation's standing in the world, and through it, to its economy and social structures. Damage of the sort that would make the party unelectable for many years to come.

Among the Trump insurgents, such sabotage would prove what they have been thinking about the Republican establishment for quite some time. They see it as having paid lip service to conservative ideas and idealism, but ever inclined to drop principle and policy whenever power or money get involved. A party corrupted by insider politics. A party for sale to political action groups, lobbies and big business. A party that makes deals. Even with devils such as Obama.

Actually, making deals is what political parties do, even if that is sometimes news to single-issue folk or zealots. Parties are umbrellas embracing the views of different interests, priorities and policies, forced to ration scarce resources around the points which seem to matter most, and because it is unable to do everything, feeling sometimes that half a loaf is better than none at all. A party itself, here or in the US, is pitched towards attracting the maximum number of supporters, rather than having a platform in which every word is a sacred text, every principle and policy completely immutable and non-negotiable. Inside a party people will argue, often bitterly, about priorities and general principles; the very fact of such a debate is often a sign of political health. But those who cannot move, who will not bend, who do not negotiate and for whom any compromise is anathema hardly eversucceed in the long run.

There's absolutely no evidence whatever that Trump is inflexible. Slippery perhaps. But changeable might well be his middle name. But his big appeal to many of his supporters is the notion that he is not beholden to the powers that be in his own party, and that he has no interest in making deals with them. At this stage in particular, Trump is campaigning against mainstream Republican ideas and values. He may well "adjust" his view, so as to go for the electoral middle if or when he gets the nomination. For the moment, however, he is the safe harbour, the asylum for the Republican dispossessed.

Mainstream Republicans have not delivered to the Tea Party sects, the hardline Christian right, gun nuts, nativists and others for decades, even as they have begged for the support of such groups, who, during the off years are virtually the only organisers and activists in the party. Mainstream Republican politicians are derided as RINOs – Republican in name only. A good many in these constituencies would themselves rather have the party go down in a screaming heap rather than support a RINO candidate. Many are past appeals for compromise, common sense or to practicality, including the pragmatic need to establish a coalition of at least 50 per cent of voters. What's the point of winning if doctrine or principle have become so far diluted that victory means nothing, they ask. Why bother?

No left-wing denunciation of the mainstream Republican Party as the party of mammon, corrupt interests and crooked deals could match for ferocity, or general accuracy, the tirades against the party by those who consider that the party has betrayed them. No reminder of how workers have been swindled by trickle-down economic nostrums is necessary. To the dispossessed, it is not just some mythic America which needs to be taken back; it is also "their" party which must be cleansed of the smug, the comfortable, the liberal and those who say the words but never deliver.

One might cavil about the way that many such people, particularly among the white working class, consider the Republicans to be their traditional party. Yet a majority have been voting Republican all their lives, or at least since 1968 when Richard Nixon began the process of capturing traditional working men and women from the Democrats. He did it by appealing to white working class unease, unease about desegregation, civil rights and Vietnam protests, and urban dysfunction. A lot of dog whistling took place.

Whites, particularly in the southern states, believed that pragmatic politicians such as Lyndon Johnson, who had long sat on their hands about the racial divide, had dumped them so as to appease middle-class liberals. Phrases such as Balmain basket weavers, champagne socialists and "the usual suspects" were not around in the US , but they seemed to symbolise not only an increasing divide between the Democrats and the old base, but also the suspicion, amply justified, that many of the new Democrats actually despised the "red-neck" working class. Obama exemplified this in 2008. Talking of workers losing old-style mass production jobs in the rust belts, he said that "they get bitter, they cling to guns and religion or antipathy to people who are not like them. Or anti-immigration sentiment, or anti-trade sentiment as a way to explain their frustrations." Even Hillary Clinton, then campaigning against him for the Democrat nominations attacked these remarks as "elitist" and "demeaning" and had her staff handing out badges saying, "I'm not bitter." Sarah Palin quoted Obama's words in her amazingly mangled speech endorsing Trump this week.

But a good deal of these Republican constituencies are bitter, even if, at this stage of the campaign, their wrath is directed at the Republican Party rather than the Democrats. They have every right to be, if only because they have been fools. Not necessarily fools for being persuaded that such smaller government was to be desired, even in an economic polity still promising to deliver special subsidies to every vested interest, and whose tax cuts were mostly focused at the very rich. Nor necessarily fools for having major reservations about free trade treaties when it appeared that the major effect was to export jobs. Nor necessarily fools for feeling uneasy about social and demographic change and the browning of America. Nor about the hollowing out of the middle class, increasing inequality and lack of economic opportunity, and a growing divide between a major part of the popular unskilled for the new economies.

But fools for listening to shock jocks, snake oil salesmen (and women) and ambitious politicians with simplistic explanations for what was happening. Ones that pinned all blame on black men in the White House, immigration by Central Americans, and conspiracies to deprive white men of their simple pleasures, such as hunting and shooting. As well as panaceas such as a massive reduction in services from government, high walls to keep foreigners out, deportation of Muslims and Mexicans, and tax incentives for already rich people. All dressed up with the usual pap suggesting that America was founded for, and intended by God only as, a republic for religious puritans, where self-reliance, hard work and piety would earn one rewards here as well as in the hereafter.

More than a few of Trump's rivals have pointed out that Trump is not a natural standard-bearer for his crusade. He may be a populist and a demagogue. But he's also a very rich man with a history of business failure and economic and social brutality to those who have trusted him.

He has no background history of association with conservative principles, causes and leaders. Nor has he, during the campaign, paid more than cursory attention to conservative ideas or even so-called "Christian" values. He is socially liberal on matters such as abortion, a key issue among the Christian right, though it has not yet been used against him and he is, in any event now prevaricating about it. He is only notionally a churchgoer or believer. He is epically vulgar, and sexist, and whether he is actually racist or not, is consciously playing as many race cards as he can.

He comes from New York, the modern Sodom as far as his constituencies are concerned. Pitching himself as one not stained by deals in back rooms, he is, in fact, a perennial insider, whose fortunes (and losses) have mostly turned on political favours over rezonings.

It is unlikely that pointing out such contradictions, or any number of ambiguities, hypocrisies or unsavoury incidents in his past will shake the confidence of those who want to believe in him. It's a matter of faith, not facts, as with evolution.

He frequently contradicts himself, and, more often, makes up stories for political effect, such as the one about parties in New Jersey cheering when aircraft attacked the Twin Towers. He is almost impervious to reasoned public argument, and simply ignores his critics by going over their heads, often by making even more outrageous and unlikely statements simply so as to distract.

One might see in him something of the Pauline Hanson and something of the Clive Palmer, but there is little evidence of either the sincere but silly rabble rouser, or the amiable but cunning political blackmailer. He's rather more the patent medicine salesman, peddling hope and confidence, but appealing rather more to the passions, prejudices and hearts of his followers, rather than to their heads or sense of self-interest.

The American contest already looks far more interesting than the impending Australian contest. It will almost certainly have more impact on Australia than the local derby. Pity, perhaps, that Australia's will occur before we know with whom our prime minister will have to deal in Washington.