CNN —  

Not long ago, there was a degree of grace and civility to politics. In this toxic presidential campaign those elements have vanished. And it was plain for all to see in the third and final debate Wednesday night.

From the moment Donald Trump and Hillary Clinton stepped on stage in Las Vegas, they did not so much as acknowledge each other. They did not shake hands. Their campaigns dispensed with the customary greeting between their spouses after the Clinton campaign sought to prevent any new Trump theatrics, like his parade of Bill Clinton’s accusers at the last debate.

From that cold introduction to their deliberate avoidance of each other as they left the stage, the two candidates spent the evening exchanging icy glares of contempt. There were substantive policy discussions, but they were laced with insults, accusations and innuendo.

This has largely been a vacuous contest that has centered on personality rather than policy. These final debates will be remembered as the denouement of the most crass, coarse and uncomfortable campaign in modern political history.

Donald Trump: ‘I will totally accept’ election results ‘if I win’

Debates in the recent past have been tense, sometimes caustic. But it is difficult to recall any like last night that displayed an utter absence of comity.

Clinton talked over Trump, letting his personal insults slide past her so she could punch her points. He repeatedly interrupted her, leaning into the microphone with pursed lips – perfectly recreating Alec Baldwin’s impression on “Saturday Night Live” – as he bellowed “wrong” to try to cut her off.

Then there were the insults and the name-calling. She charged Trump would be Russian President Vladmir Putin’s “puppet.” He retorted that Putin had outsmarted and outplayed her as secretary of state.

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She called his rhetoric on nuclear weapons “terrifying.” He called her “a liar,” framed her family’s foundation as a “criminal enterprise” and described her campaign as “sleazy.” Trump capped the evening by muttering into the microphone that she was “a nasty woman” as she landed one of her final attacks.

Of course, the most breathtaking moment of all was when Trump sowed the seeds of discord for the aftermath of the election. Contending that the election is “rigged” and the media has “poisoned the minds of voters,” he refused to commit to accepting the results of the election.

“I will look at it at the time,” Trump said when Chris Wallace of Fox News, the debate moderator, asked if he would “absolutely accept the result” of this election. “I’m not looking at anything now. I’ll look at it at the time.”

“But sir, there is a tradition in this country,” Wallace persisted. “In fact one of the prides of this country is the peaceful transition of power and that no matter how hard fought a campaign is, that at the end of the campaign the loser concedes to the winner.”

“What I’m saying is that I will tell you at the time,” Trump replied. “I’ll keep you in suspense. OK?”

Amidst a hailstorm of criticism, even from fellow Republicans, Trump appeared to backtrack – a little – on Thursday afternoon by saying he would accept a clear election result.

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As with all of Trump’s cryptic statements, we won’t know exactly what that means until the moment arrives on the night of November 8.

In the meantime, the two candidates meet again Thursday night at the famed Al Smith dinner in New York – an event that is meant to set partisan politics aside for one night in the heat of the campaign.

The 2012 Al Smith dinner is remembered for the gracious remarks by Mitt Romney and Barack Obama about one another.

Romney noted that night that it would be easy to let healthy competition on the campaign trail “give way to the personal and the petty.”

“But fortunately, we don’t carry the burden of disliking one another,” Romney said. “Don’t tell anyone I said so but our 44th president has many gifts and a beautiful family that would make any man proud.”

Obama, in turn, spoke of how he admired Romney “very much as a family man and a loving father, and those are two titles that will always matter more than any political ones.”

Obama also noted that he and Romney shared the hope that the next four years would “reflect the same decency and the same willingness to come together for a higher purpose that are on display this evening.”

Clinton and Trump will be seated one chair apart this evening. Whether they can recapture that spirit of civility – even just for one night in this soul-crushing campaign – is anyone’s guess.