Jeff Greenfield is a five-time Emmy-winning network television analyst and author.

There was a half-hour or so when it looked as if Donald Trump had finally absorbed the hopes, pleas, entreaties and desperate groveling of his advisers and most ardent GOP supporters and decided to behave like a serious, responsible candidate for president of the United States.

His voice was pitched low. He gave an answer on the Supreme Court that followed the mainstream conservative line, saying his nominees “will interpret the constitution the way the founders wanted it interpreted, and I believe that’s very important.” He even cited by name the Court’s Heller decision, which established an individual right to bear arms.


Trump cited examples to make his point about the costs of illegal immigration. (“I was up in New Hampshire the other day … heroin is pouring across their borders"). When Clinton tried to turn a question about the WikiLeaks revelations in to an attack on Russia, Trump responded: “Great pivot off the fact that you want open borders.”

And then, about a half-hour in, the Donald Trump we have seen for the past year and half began to emerge: slowly at first, with the interruptions (“Wrong!”) and then with increasingly depressing familiarity, right up until the point at which he refused to say he would recognize the results of the Nov. 8 election—plainly the headline of the night—and then spewed out: “Such a nasty woman!”

When the issue of Russian interference with the election came up, Trump didn’t acknowledge this was happening and then brushed aside the concerns of national security officials who have asserted that it is. All he said was: “I never met Putin. This is not my best friend. But if the United States got along with Russia, it wouldn't be so bad. Let me tell you, Putin has outsmarted her and Obama at every single step of the way.” When Clinton confronted him on his casual approach to nuclear weapons, he began what became a steady stream of “liar” accusations. Trump also appeared to oppose the U.S.-backed assault on Mosul, saying that only Iran would benefit (though he didn’t explain how), even though he’s based his presidential campaign on the pledge that he would destroy the Islamic State.

And when the question of his treatment of women arose, he did not even bother to follow moderator Chris Wallace’s question and raise the issue of whether she had participated in attacking the women who had accused Bill Clinton of bad behavior.

Instead, he ignored the accusations of nine different women and said, “I didn't know any of these women. I didn't see these women. These women, the woman on the plane, I think they want either fame or her campaign did it. … If it wasn't, they get their 10 minutes of fame, but they were all totally—it was all fiction. It was lies, and it was fiction.”

But nothing demonstrated the limits of Trump’s ability to behave like a serious candidate than the simple question of whether he would abide by the results of the election. His running mate, his campaign manager, the GOP speaker of the House — all have said in no uncertain terms that of course they would.

Trump’s answer: “I’ll look at it at the time. What I've seen is so bad. The media is so dishonest, and so corrupt and the pile-on is so amazing.”

An incredulous Wallace said: “But, sir, there is a tradition in this country, in fact, one of the prides of this country is the peaceful transition of power and no matter how hard fought a campaign is that at the end of the campaign the loser concedes to the winner. … Are you saying you're not prepared now to commit to that principle?”

“I'll tell you at the time,” Trump said. “I'll keep you in suspense, OK?”

And that gave Clinton the opening for her best moment of the debate.

“It just shows you're not up to doing the job,” she said. “Let's be clear about what he's saying and what that means. He's denigrating and talking down our democracy. I, for one, am appalled that somebody who is the nominee of one of our two major parties would take that kind of position.”

Perhaps if there had been four or five more debates scheduled, Trump would have been able to conduct a full, 90-minute debate worthy of a major party nominee for president. But this was the final debate, and Trump delivered an underwhelming performance at a moment when he’s well behind in most polls only three weeks from the election. In the end Trump simply could not help being ... Trump, which almost surely ended his last hope of victory.