Americans at last have a head-to-head comparison of their contenders for the White House. Vice President Harris and President Trump are busy spinning their performances in what may be their only debate, each using it to help paint visions of a dark future if their opponent prevails. 

Unlike the faceoff between Trump and President Biden, this one at Philadelphia’s Constitution Center started out with a respect and goodwill: A handshake, signifying no weapon. Ms. Harris urged Americans to “turn the page” on acrimony. With those outstretched hands, a bit of that comity was restored.

While Ms. Harris offered no assessment of her performance, Trump exclaimed on social media that he “thought it was my best debate ever, especially since it was three on one.” The former Clinton pollster Doug Shoen, in a text to me after the debate, also cited the “assistance of the two ABC moderators.” 

Mr. Schoen judged it “a win for Harris” but he doesn’t “think it will ultimately affect the outcome of the race.” The dynamic of a man facing a woman loomed large. In yesterday’s News/SurveyMonkey poll, Ms. Harris led among women by 13 percentage points and Trump among men by eight points, accounting for the vice president’s three-point lead overall.

In the 1988 election, a Washington Post columnist, Ellen Goodman, said President George H. W. Bush reminded many women of their “first husband” while Governor Dukakis reminded them of their second, “the one she looked at long and hard.” 

Americans aren’t getting much of a courtship with Ms. Harris, but they’ve known Trump for decades. The former president sought to remind voters of the good times they’d had together and pointed out that despite Ms. Harris’s wooing, she’s in power now and not delivering. He urged her to go to Mr. Biden, “wake him up,” and enact her plans.

Republicans feared and Democrats hoped that Trump would bully Ms. Harris, or not use the pronunciation of her name she prefers. In the end, he didn’t address her by name or brand her with a derogatory replacement. He only grew heated when challenged by the moderators about losing the election and his plan for Afghanistan. 

It wasn’t the calamity a direct confrontation might’ve been. Expect post-debate coverage to focus instead on his claim that Haitians in Springfield, Ohio, are eating pets. When one moderator, David Muir, said the “city manager there” had received “no credible reports” of such behavior, Trump stood his ground and cited accounts he’d seen on TV. 

On having questioned Ms. Harris identifying as Black, Trump backed off and took his lumps. “I couldn’t care less,” he said of how his opponent presents. “Whatever she wants to be is okay with me.”  Ms. Harris said it was evidence that her opponent had “attempted to use race to divide.”

The muted microphones, which Ms. Harris fought to have turned on, gave Trump an opening to borrow an old zinger that his opponent had telegraphed was coming again. At one point in the 2020 debate with Vice President Pence, Ms. Harris had said, “I’m speaking.”

The Biden campaign emblazoned the quote on t-shirts, coffee, mugs, and other memorabilia. Aware it was coming, Trump laid in wait for Ms. Harris to begin interrupting him. “I’m talking now,” he said. “If you don’t mind. Please. Does that sound familiar?”

The barb knocked the vice president off her game. She had already seemed nervous meeting the former president for the first time, her mouth audibly dry. About half an hour into the 90-minute bout, she began to find her groove. She cast Trump in the worst light possible and objected to his attempts to do the same.

“I am not Joe Biden,” Ms. Harris said. The remark showed that the unpopular incumbent — who, Trump claimed, “hates her” — is weighing down her campaign. The vice president recovered her footing speaking about restoring, via legislation, the Roe v. Wade precedent as Trump did warning about illegal immigration and what he called “weakness” that led to the invasions of Ukraine and Israel.

Ms. Harris often smiled in the two-shot while watching Trump speak. This gave the impression that the former president, who stared straight ahead, was the voice of authority. It also visually undercut Ms. Harris’s warnings about the danger Trump poses to the nation. She’d have been better served by adopting Mr. Biden’s scowl. 

Supporters of Ms. Harris worried that she’d be overprepared, and at times she did sound canned. Whether her defense of reversals on many issues — “12,” or “maybe 14,” Trump said — such as decriminalizing illegal border crossings, legalizing drugs, and ending private health insurance succeed will depend on how much voters trust her.

On the issue of fracking, key in pivotal Pennsylvania, Ms. Harris slipped one past her opponent. “As vice president,” she said, “I have not banned fracking.” Of course, she has no power to do so under the Constitution. The dodge avoided the moderator’s question. It was one of many openings that Trump, who rejects traditional debate preparation, failed to exploit.

Multiple times, Ms. Harris promised to “cut taxes.” However, her credits for children or first-time home buyers and deductions for new small businesses are not the same thing. They insert the government into the equation and require citizens to spend the money first.

Ms. Harris repeated themes about her “opportunity economy” and being raised a child of the “middle class.” Repetition might have driven the points home or voters may have found it tiresome. The same will be true of Trump’s focus on the crimes committed by those in the country illegally. In the end, talking points carried a night where sparks failed to fly. 

Ms. Harris won a boost in stature just by sharing the stage with the former president and holding her own. Voters now face a choice: Give their first husband a second chance or pick this new suitor, overcoming concerns that she’s just saying what they want to hear — and trusting her not to break their hearts.