Trump was Trump in his debate with Kamala Harris — which is why he came across so poorly

It was ugly. It was inane. It was tone-deaf and uncouth.

And that’s just briefly summarizing Donald Trump’s performance in Tuesday night’s debate.

The big question going into his face-off with Kamala Harris was which iteration of the perennially aggrieved, perpetually prevaricating ex-president would show up.

The one who manages to restrain himself just long enough to convince at least some of those who don’t much follow politics that, heck, he’s not all that unreasonable?

Or the full-on, unhinged, unexpurgated Trump who believes facts can be shaped like pottery, reality is what he claims it to be, and no insult is too low to fling at his opponent?

It was most definitely the latter who bulled his way onto the stage at the National Constitution Center in Philadelphia, where Trump stoked the passions of his fervent MAGA followers but did little to reach beyond his unshakable political base.

The Jan. 6 insurrection? Not Trump’s fault.

“I had nothing to do with that other than make a speech,” he said, lamenting the fatal shooting of rioter Ashli Babbitt for attempting to break into the House chamber — and saying not a word about the police officers killed and injured in the unlawful attempt to overturn the 2020 election.

He actually won that 2020 contest, Trump insisted. There was “so much proof,” he claimed, even though dozens of courts and his own administration’s election security experts repeatedly found his claims of widespread fraud to be just so much gaseous venting.

As for his insistence that Harris — who is Black — had only recently “turned Black,” Trump explained: “I read where she was not Black … and then I read that she was Black, and that’s OK, either one was OK with me. That’s up to her.”

Which was incredibly magnanimous.

And on it went.

President Joe Biden secretly hates his vice president, Trump asserted. Immigrants in Ohio are kidnapping households pets to provide themselves a square meal. (Which is as absurd as it sounds.) Harris hates Jews and Arabs, which, one supposes, is a way not to take sides in their eons-long conflict — though that was not the point Trump was trying to make.

All that bluster overshadowed Harris’ vague response to questions about her position on issues such as fracking and eliminating private health care insurance, which have shifted since she ran much further to the left during her unsuccessful 2020 presidential bid.

Trump couldn’t help himself, even when his bad behavior didn’t help himself.

The vice president, who finally seems to be settling to Earth after the meteor ride that followed her installation atop the Democratic ticket, landed in Philadelphia needing to do a few things.

One was to gently distance herself from President Biden, which she attempted by pointing out — irrefutably — that she is, in fact, not President Biden. (It’s not that simple, however.)

Another was to flesh out her policy portfolio, which she did, to an extent, by talking about proposals such as expanded housing subsidies, a $6,000 child tax credit and a $50,000 tax break for small businesses.

Above all, Harris had to demonstrate — as a woman, and a slightly built one, at that — that she possesses the brawn and backbone to lead the country. A way to make her case was by showing the strength and spine to stand up to the brash and bullying Trump, which she easily accomplished.

It was Trump who ended the night with a bead of sweat on his upper lip and the tetchy demeanor of someone whose antagonist had clearly burrowed under his skin.

A remark about crowd size — which seems to trigger the former president in a deeply Freudian way — had Trump sputtering how “no one” goes to Harris’ rallies and heatedly denying her assertion that his act, and audiences, were growing thin.

“People don’t leave my rallies,” Trump bleated, insisting despite abundant proof to the contrary that his crowds are the biggest in American political history.

She mocked his Midas-businessman claims, noting Trump inherited a fortune from his real-estate-developing father and filed for bankruptly a half dozen times.

“Donald Trump was fired by 81 million people,” Harris said of the 2020 election, “and clearly he’s having a very difficult time processing that.”

She kept on.

World leaders, Harris said, laugh at Trump behind his back and call him a disgrace.

It’s hard to imagine the last time Trump, who cossets himself with an entourage of fawning sycophants, has been spoken to in that fashion.

People tend to forget, because Biden was so awful, how badly Trump performed in their June debate. Once again, he issued a fire hose of lies: about the rates of crime and illegal immigration; about Russian dictator Vladimir Putin endorsing Harris; about China building “massive” auto plants in Mexico and stealing a torrent of U.S. jobs; about “after-birth abortions” taking place with the support of Democratic politicians.

(For all the what-abouters out there, Harris made a dubious claim about there not being a single American soldier on active duty in a combat zone, which overlooks those in harm’s way in Iraq and Syria, among other countries. She also wrenched out of context Trump’s comment about “a bloodbath” commencing if he loses the election. He was talking about the economic impact on the auto industry.)

Biden’s abysmal showing pushed him out of the presidential race. Harris’ strong debate performance won’t have as dramatic a result. It’s hard to see her gaining a huge surge of support. The country is simply too divided along partisan lines for that to happen.

But Harris certainly didn’t hurt her candidacy and probably helped herself Tuesday night. In a close contest, that has to be considered a victory.

Mark Z. Barabak is a columnist for the Los Angeles Times, focusing on politics in California and the West.