The best news out of Tuesday night’s nationally televised debate is that, once in a while, we heard a candidate for president of the United States actually plunge his way through a complete sentence without getting mugged or tripping over the truth.

The worst news is that this national disgrace was allowed to continue after President Donald Trump quickly made it clear he came to play by his own rules, and the hell with what anybody thought about it.

Chris Wallace, the Fox anchor who allegedly moderated the debate, tried to rein in the president. He got nowhere.

Wallace works for Fox News, which is generally indistinguishable from the Trump campaign. Yet here was Trump, telling Wallace, “I guess I’m debating you, not [Joe Biden], but that’s OK. I’m not surprised.”

Yes, poor Donnie, always the victim.

And then, a moment later, there was the former vice president and Trump’s Democratic rival, interrupted for about the 27th time, telling Trump, “Will you shut up, man?”

Wonderful. So now, “shut up” is part of our debate lexicon?

This is the best of America?

At the end of 90 minutes, I wanted to weep for the future of the country.

Shame on all of us if this is how we discuss our future, in the midst of 200,000 deaths, and seven million COVID-19 infections, and millions of unemployed wondering if they can pay their rent, and millions more wondering about health care and abortion with a new Supreme Court imbalance, and thousands marching in the streets over racial tensions.

Yes, Trump was by far the evening’s biggest culprit. He brought all the dignity of a sullen high school sophomore hanging out on a street corner, hoping that the sheer volume of his voice would keep any dissenting opinions out of the discussion.

We’ve come to expect this of him, but we imagined he’d try to behave a little better with so much on the line.

What made the evening worse was Biden’s response. He let Trump get away with so much of the bombast. We wanted Biden to say, “You’re the leader of the free world, but you’re not the king. I get a chance to talk, too.”

And I know what some people will say: he let Trump be Trump, and therefore exposed this man for what he really is –- a bully, a mean spirit, a man intentionally dividing a nation to save his job.

But surely, Trump’s not going to win any of those suburban housewives he’s trying to seduce with this kind of childishness. Surely, he’s not going to convince any Democrats to cross over with this kind of boorishness.

His performance was demeaning for the whole country. It lowers our standards – of politics, and of civility.

And Joe Biden stood there silently when, frankly, you wanted him to raise his own voice and level Trump with a zinger. Instead, he stood there as though paralyzed.

Does a national debate get any more absurd than Trump bringing up Biden’s alleged college academic standing? Trump’s the guy whose own family says he hired some smart kid to take his SAT test for him.

Does a national debate get any lower than Biden lamenting one son, the late Beau Biden, who served in war and later died of a brain tumor, and Trump interrupts him to attack Biden’s other son?

Does it get any more stupid than Trump saying he was being “sarcastic” last summer when he suggested people ingest disinfectant to fight the coronavirus? We have the videotape, Mr. President, it’s there for everyone to see. It wasn’t sarcasm. You were delighted by your own sheer idiocy.

Does it get any more hypocritical than Trump declaring, an hour into the debate, “We take care of our veterans?” This is the guy who called American war dead “losers” and “suckers.” That was a moment for Biden to say, “My son served in Afghanistan. He was not a loser. I want an apology to him and all the others who have served.”

Does it get any more frustrating than that moment when the talk got around to Trump’s taxes? As the New York Times has been reporting, Trump’s alleged business success is a myth. He’s got personal loans of more than $400 million that will come due in the next couple of years.

But, to whom? We don’t know — and the moment to make him tell us slipped away. And so we don’t know if any of these massive loans make the president of the United States a possible target of blackmail by some foreign power.

This self-described billionaire paid no federal income taxes in 10 years out of 15, and only paid $750 in two other years, the Times reported. Four years ago, when it was pointed out that he hadn’t paid taxes, Trump said this made him a “smart” person. Does that mean every person who pays taxes is stupid?

We don’t know. Biden stood there silently, when we wished he might have echoed comedian Trevor Noah’s remark about the Times income tax story, that Trump paid $750 to his country but $130,000 to a porn star.

But the moment slipped away.

“Show us your tax returns,” Biden said.

“I built a great company,” Trump shouted over him.

Are you kidding?

It was just one more rant by Trump. There were moments that felt like that scene in the original version of “The Manchurian Candidate,” where Laurence Harvey’s stepfather stops a U.S. Senate hearing by shouting out some nonsense about the number of communists in the State Department. The whole story’s a dark parody of McCarthyism.

But in retrospect, it feels like a sneak peek at Trumpism, which millions of us watched Tuesday night, and wanted to weep over such a sight happening in America.    

A former Baltimore Sun columnist and WJZ-TV commentator, Michael Olesker is the author of six books, including “Front Stoops in the Fifties: Baltimore Legends Come of Age” (Johns Hopkins University Press).