Sane people can place hands over ears and scream to block out the real world, but there is a real possibility that Ug the Unpleasant could still beat Hillary Clinton in November.

Michael Moore, the veteran polemicist, put it well in a recent blog. "You are living in a bubble that comes with an adjoining echo chamber where you and your friends are convinced the American people are not going to elect an idiot for president," he wrote.

Mike then detailed five reasons Trump could win before closing with an exasperating quote from a fan. “We have to vote for Trump. We have to shake things up,” his confused pal said. Shaking up Washington was the only thing that mattered. By this logic, unleashing a pack of underfed cougars into the Capitol Building would do just as well.

Anyway, we can imagine scenarios in which politics would be irrevocably altered by a Trump victory. Who knows how we might appoint our leaders in a post-Apocalyptic wasteland. We might burn the tallest tribe member in a wicker structure and pray to the resulting ashes for guidance. Future primitive societies might appoint a goat or a hedge as their chieftain. After all, their predecessors -- who flew in great iron birds and spoke across oceans – did a great deal worse in their dying years.

Let's not get ahead of ourselves. For the past year, Trump has been tearing up the rulebook in a fashion that, for any other politician, would have proved suicidal. One mildly deranged conspiracy theory suggests that Trump is acting out the first part of the Song For Europe episode of Father Ted.

Beginning the campaign as a bit of a lark, he first proved more successful than he hoped and then more successful than he feared. If things went on in this fashion he might actually have to become president. Who’d want that? The rudeness, disingenuousness and inconsistency were attempts to sabotage his own campaign. But nothing seemed to stick.

Three words need to be banished from the 2016 political lexicon: “Even for Trump”. We have repeatedly read them in considered reports and hastily composed social media posts over the past year.

It seemed appalling “even for Trump” when he impersonated a disabled New York Times reporter.

It was unthinkable "even for Trump" to suggest that, because he got captured, John McCain wasn't really a war hero. It was bizarre "even for Trump" to argue that Megyn Kelly, a Fox reporter, was having her period when she asked him some mildly disobliging questions.

The “EFT” qualifier has never been so visible as it was during Trump’s ignoble engagement with the Khan family. It implies no trivialisation of the offense to argue that it was not “disgusting even for Trump” to make unkind and Islamophobic remarks about the mother of a fallen Army officer. It was certainly disgusting, but it was entirely in character with what had gone before. He remained unbowed and unapologetic. Why would he be otherwise? Earlier outrages had triggered a surge in popularity. This is what his supporters crave.

So, has the Trump campaign permanently changed political discourse? It looks that way from certain angles. For all George W Bush's inadequacies, he would never have suggested that the father of a dead soldier was silencing his grieving wife. Ronald Reagan had manners. Jimmy Carter was equally polite in public. It could be argued that, since the last war, the US has elected only one belligerent psychopath (not a bad hit rate for political life) and that nutter, Richard M Nixon, issued his most Trumpian rants in private.

Each of the missteps listed above would have been enough to kill the candidacy of any other candidate. Yet Trump trundles on. It has become hard to imagine what enormity would now deserve the “EFT” qualifier. If he were found huddled over a butchered corpse with a blood-stained cleaver in his tiny hand then I suppose we might think that dreadful “even for Trump”. But I wouldn’t bet on the offense severely damaging his popularity among core voters.

The most committed Trumpistas savour their idol's reputation as a political bandit. The very fact that the "Mainstream Media" are upset about Trump yelling abuse at Mexicans or threatening to bar Muslims proves that he is still doing the business.

There is, however, some good news here. Like any other empty performance, the Trump derangement will eventually become as familiar as the polished murmuring of the Republican elite. His approach thrives on novelty and, by definition, novelty eventually outstays its welcome. Brave rogues may have settled America, but calm bureaucrats civilised it.

Trump probably hasn’t changed political discourse forever. But that’s no reason for complacency.