The Trump assassination attempt drives a line through the fabric of ...

A bitterly divided United States has just become dangerously divided.

This is a time for anyone with influence in the US to exercise their power to calm a shaken nation — rather than to stoke divisions and fears.

The assassination attempt on Donald Trump has driven a new and extremely disturbing fault line straight through the fabric of American democracy — a fabric which was already fraying.

Follow our live coverage of the attempted assassination of former US president Donald Trump. 

The fragility of American stability and democracy is demonstrated by contemplating that had the shooter in Pennsylvania succeeded in killing Trump, would it have unleashed civil unrest in the US?

Had one bullet been a few centimetres closer to Trump's brain — rather than grazed his ear — it could have changed US history and may have sent the US into a spiral of chaos and possibly violence in the streets.

American democracy and good governance was already under pressure. 

Joe Biden — a frail, incumbent president who struggles to get through a one hour news conference without misspeaking the name of a world leader or his own vice president — was fighting in the polls beside Trump, a convicted felon who has promised the powerful gun lobby, the National Rifle Association, that should he win in November he will not curtail the easy access Americans have to guns. This is surely an uncomfortable irony, given Trump was almost killed by a gun.

US media reported that Trump shouted "fight" as he left the stage — defiant, fist-clenched and with blood on his face. That powerful image will now become a symbol of his attempt to again be elected president.

Yet the stress on US democracy has just deepened. Trump supporters should not heed the apparent call of their candidate — if in fact he did shout "fight". 

Instead this is a time for leaders from all walks of life in the US to genuinely try to calm a shaken public.

Those with an obligation to try to sooth this anxious nation include Biden, Trump, the media and even commentators on social media — although the hope of social media playing any sort of calming role is probably a forlorn one.

Following the assination attempt, Donald Trump was keen to show his defiance to the rally crowd.(AP: Evan Vucci)

Following the shooting, yet again social media showed how dangerous it can be. 

Conspiracy theories quickly began to circulate and suggested Trump's secret service detail had deliberately been degraded to expose him to physical danger. The sick subliminal message is that it was the fault of the Biden administration. This conspiracy theory is demonstrably untrue.

Trump himself is a passionate advocate for the professionalism and skill of his secret service detail and personally devoted to them. In recent times that structure of protection has been upgraded as the election nears.

The video of the chaos in Pennsylvania which followed the assassination attempt shows how secret service agents literally put their bodies on the line to stand between Trump and the likely direction from which the bullets came. 

At a time when the agents did not know that the shooter was dead, several stood alongside the vehicle into which Trump was rushed. They put themselves in the line of likely fire willingly and in accordance with their training.

Meanwhile President Biden did the right thing by telephoning Trump to express his support and return to the White House. And former president Barack Obama also hit the right tone by saying all Americans should be "relieved" that Trump was in good health.

It is important that Trump himself also tries to calm tensions.

A member of the public who exercised their democratic right by attending an open and legal political rally is now dead. That alone could inflame some of the more extreme Trump supporters.

Shortly after the shooting presidential historian Tim Naftali said the US was now in "a fragile moment" and that this was a time for careful words by opinion makers and influencers.

He told CNN this was a time for those who shaped opinion to "dial down" rhetoric and not a time for "poison and hatred". 

"This is a time to stop hating each other", he said.

And those whose views fit the extremes of US politics need to realise that this is deadly serious. Trump may have escaped the attempt on his life but bullets can kill, and did take the life of one man who attended the rally in Pennsylvania. The shooter was also killed.

And in a country awash with guns, words can foment hatred, encouraging unhinged people to take to violence.