The news clips of Donald Trump's supporters chanting "send her back!" during the US president's rally in North Carolina on Wednesday make for some pretty chilling viewing.
The footage, which shows Trump's typically self-congratulatory and self-delusional spiel being interrupted by the rising volume of a seemingly spontaneous chorus coming from his audience, lasts for all of 13 seconds.
Nevertheless, it has turned out to be 13 seconds that has shaken America to its very core. It is not difficult to understand why.
To watch what unfolds is to get a glimpse of hatred in its purest and most unadulterated form.
What it reveals is the power of the mob; the viciousness of a pack hunt.
It shows exactly what happens when you play the race card.
The sight and sound of hundreds of Trump loyalists baying like wolves for their hero to sign a deportation order and chuck a 37-year-old Minnesota woman out of the country without cause or reason awakens unwanted memories of racial segregation and the struggle to shake it off.
No matter that, Representative Ilhan Omar is a member of the United States Congress. No matter that she is a United States citizen. She is the "her" in the "send her back!" refrain. When Trump's simple-minded acolytes (and Trump, for that matter) say "back", they don't mean Minnesota. They mean Somalia, her place of birth.
Omar is one of four Democrat Congresswomen who have been on the receiving end of Trump's racist bile. She has been the one who has copped most of it, however.
All four had been adamant that they not respond in kind; that they not "swallow the bait."
Omar finally cracked, however, calling the president a "fascist".
That was exactly what Trump wanted to happen.
Trump may be a very sick joke who has foisted himself on the American people, but he is not a fascist. Moreover, his supporters in crucial swing states like North Carolina will resent him being labelled as such.
Those who readily swallow the garbage mouthed by Trump would argue that the "send her back!" refrain is nothing more than a variation on the cry of "lock her up" directed at former US presidential candidate Hillary Clinton during the 2016 presidential election.
But playing politics with race is potentially many more times explosive than querying what someone should or should not have done with their email accounts.
Trump's defenders would also argue that the president was not being serious; that he was playing a political game. In that vein, it's ludicrous to suggest or think any of the Congresswomen would ever be sent "home" — whatever that means.
Given three of the women were born in the United States, they are already home.
It is absurd, yet the Trump presidency is a daily Theatre of the Absurd.
That was encapsulated by his efforts to distance himself from the sickening chorus which erupted while he was at the podium in North Carolina.
The following day he declared that he "felt a little bit badly about it" and that he had "started speaking very quickly’" in order to stop the chanting.
The truth — a commodity that has long been at malnutrition levels in the White House these days —is very different.
Trump did nothing to silence the throng. His demeanour was of someone delighting in the interruption — so much so that one could be excused for thinking the incident had been concocted beforehand.
No one should be fooled by Trump's apparent contrition. And he showed precisely why less than 24 hours later by executing a complete U-turn on that stance by praising the crowd at his rally as "incredible".
It is an age-old political trick to say or do something outrageous and then execute a partial retreat amidst the subsequent uproar.
The initial outburst or action almost always gets far more attention than any later expression of regret. It is taking things into a whole new dimension to reverse a reversal, however.
In the world of politics, consistency in one's statements is expected as an absolute given.
In Trump's world, being inconsistent is not a negative. It is the norm.
There is only one rule in the Trump White House. That rule is that there are no rules.
The upshot is that the most powerful position in the world is in the hands of a pathological liar and an unapologetic racist - not a good combination.
The unspoken message from this week's events is that nothing is off-limits in his seeking a second term as president.
Trump is promising to run the nastiest and dirtiest of re-election campaigns. He can be relied upon to be 100 per cent consistent in that regard.
There is method amidst this seeming madness, however. In guaranteeing that the four Congresswomen got massive media exposure, Trump has been endeavouring to build a picture in voters' minds of a Democratic Party which is full of left-wingers and thus out of touch with Middle America.
Trump must be careful, however. The office of president is really two jobs; there is the president as the partisan politician and the president as the non-partisan unifier of the nation.
The two roles frequently overlap. They can often have competing and contradictory objectives.
Trump's understanding of that notion is mixed. In promising to "make America great again", he has got things completely right in terms of the public mood.
In playing the race card, he has got things entirely wrong.
Trump's default setting is hardly as a a unifying force. He is a force of rancour and division.
His vision for America's future extends about as far as he can drive a golf ball.
Soon enough, Middle America will tire of the rhetoric and the hollow sound of an empty vessel.
But not yet. He has three things going for him in the lead up to the presidential election in November next year. The American economy is still booming. That means jobs. That might change. Despite every Jeremiah on the planet warning for months of a pending trade war and global recession, it hasn't happened yet.
The Democrats are in disarray. They fear that any attempt to impeach Trump will backfire.
His own Republican Party has severe misgivings about being leg-ironed to him. But that party has already nominated him as its candidate next year. It is stuck with him.
Nevertheless, it is sad irony that in the same week that the United States is celebrating its greatest technological achievement — the landing of two men on the Moon and then returning them safely to the Earth — the nation's attention has also been focused on someone whose mentality is a relic of the Stone Age.