Unlike many previous presidential debates, there were no killer moments. There was no projection of hope and vision, as with Kennedy, Reagan, Clinton or Obama, juxtaposed against an opponent's shiftiness, ineptitude or past-their-use-by-date demeanour.

Instead, Trump did what he always does: disrupt, lie, generalise, exaggerate, evade, deflect, and spout delusions about the "achievements" of his administration. It was hardly a debate at all.

The moderator, Fox News's Chris Wallace, seemed like an exasperated primary school teacher, dealing with a difficult schoolboy disrupting the class and preventing any education.

At one stage, Trump had interjected during Biden's attempted answer so many times that Wallace admitted he had forgotten the question. He admonished Trump and drew a "what about him?" reply. All Wallace could do is point out: "Frankly, sir, you have been doing the most disruption."

Surely, given Trump's innately disruptive nature, there is only one way to ensure there is some value in the next two encounters. That would be to provide the moderator with a switch to turn off the microphone of either candidate when they interject.

We were not treated to the usual audience monitoring, because there was no audience to speak of. So, it was hard to say who "won". A CNN poll said 60 per cent of respondents thought Biden won. But the sort of people who view debates are the sort of people who are interested in politics, policy and the future of their country anyway - so the result would have been skewed Biden's way and is hardly indicative of national opinion.

But the debate and that poll do confirm one thing: about 40 percent of the electorate are rusted-on Trump supporters who do not care about truth or the public interest.

To them it would not matter if Trump shot someone on Fifth Avenue, as he so famously said, or if he was responsible for 200,000 COVID-19 deaths, as he so famously is, or if he spouted ever more delusional assessments of his "achievements" and ever more promises that turn into just wishful thinking. Indeed, that conduct just rusts them on even more.

But more significantly, over the past four years, Trump has, through his conduct, rusted on more and more other voters - on to any candidate but him.

In the debate, he continued his delusions. No other president "has done more than I have done" in three-and-a-half years, apparently.

"No one has done more" for coloured people, other than Lincoln. "No one has done more" for the economy and so on.

He continued his outright lies. When Wallace tried to pin him on specifics (how much did he pay in federal income tax in 2016 and 2017), he replied "hundreds of millions of dollars". He paid just $750.

He falsely claimed that 180 million people would lose their private health insurance under Biden. Private insurance remains an option under Biden's plan.

Only the rusted-on would believe Trump's claim he has made insulin "as cheap as water", or his promise that a COVID-19 vaccine would arrive soon and be administered 200,000 people at a time by the military. They are the same rusted-on who believed in March that COVID-19 would, as promised by Trump, disappear by Easter.

Wallace's attempt to find out if Trump accepted human-caused global warming resulted in Trump deflecting to forest management.

Ultimately, though, Trump's attempt to turn the debate into a dogfight to avoid scrutiny and to rile his opponent into spending more time hosing down provocations was nowhere near as effective as it was when he was a presidential challenger in 2016.

Biden, though clearly exasperated, only rose to the bait occasionally, calling Trump a "clown" at one point before correcting himself: "It's hard to get any word in with this clown. Excuse me, this person."

Once, after several interjections, Biden said "Will you shut up, man?" But most viewers would rate that as understandable.

Overall though, Biden correctly said of Trump's attempt to rile him: "You picked the wrong guy on the wrong night at the wrong time".

True, Biden stumbled over some words a few times and had to rephrase, but it was nothing out of the ordinary and certainly nothing matching the incoherence of Trump's half-completed sentences, Twitterspeak, and narrow vocabulary.

READ MORE:

For Trump, the Paris Agreement is "a disaster". Obamacare is "a disaster". Everything he dislikes is "a disaster". On the environment, "we are doing phenomenally". On COVID-19, his performance is "phenomenal".

The debate just convinced the already convinced or left people unmoved. But, importantly, in that sense, Biden won, because on the trajectory of the opinion polls (even allowing for 2016 aberrations), Trump needs big movement his way if he is to get a second term.

By reverting to his natural position of disruption, Trump denied himself that chance. But, if truth be told, the chance is probably not there anyway. An incumbent must credibly defend his achievements and project a vision or a continuing vision. But there is no wall, no repeal and replacement of Obamacare, and the economy is faltering.

As to a continuing vision, there was no evidence of it whatsoever on the Trump side in this debate.

But does a challenger like Biden need the knockout blow or killer moment, which he did not deliver in this debate?

Biden is no Ronald Reagan or Bill Clinton, whose charisma and charm cast their incumbent opponents into the shadow of defeat. But then, he does not need that charm or charisma, because his opponent is not a Jimmy Carter or George H. W. Bush - essentially decent people who put their country before themselves.