Tuesday’s vice-presidential debate was supposed to be the last set-piece moment of Campaign 2024 before the final sprint to Election Day. It was all but overshadowed by the transfixing images of Iranian ballistic missiles confronting Israeli defense systems in the darkened skies over Tel Aviv and Jerusalem.

Mr. Netanyahu vowed retaliation — “Iran made a big mistake, and it will pay for it,” he said — while Ms. Harris was steadfast in what she called her “cleareyed” condemnation of Iran, denouncing it as a “destabilizing, dangerous force in the Middle East.”

Her running mate, Gov. Tim Walz of Minnesota, was left to frame the issue of a looming regional war as a test of character.

“What’s fundamental here is that steady leadership is going to matter,” Mr. Walz said in the debate. “It’s clear, and the world saw it on that debate stage a few weeks ago. A nearly 80-year-old Donald Trump talking about crowd sizes is not what we need in this moment.”

But any dreams of a triumphant diplomatic breakthrough to end the hostilities, bring home the remaining Israeli hostages in Gaza or even get peace talks on track in the waning days of the Biden administration were atomized along with that hail of debris from shattered Iranian missiles raining over Israel.

It was a moment the Republicans were not going to waste.

“As much as Governor Walz just accused Donald Trump of being an agent of chaos, Donald Trump actually delivered stability in the world,” Senator JD Vance of Ohio, the Republican vice-presidential nominee, said on Tuesday night.

To be sure, American voters still put foreign policy well down the list of their highest priorities, far below the economy, abortion, inflation and character. But to Mr. Trump, the conflict in the Middle East is part of a much larger narrative that he has been weaving the entire campaign.

He has said repeatedly that feckless Democratic leadership in Washington has let events spin out of control on matters like Afghanistan, Israel and Ukraine abroad; the U.S.-Mexican border; and the price of groceries at home: All was peaceful and prosperous when he was in power, and his strong hands on the wheel would bring peace and prosperity back.

“Look at the World today,” Mr. Trump wrote on social media on Tuesday. “Look at the missiles flying right now in the Middle East, look at what’s happening with Russia/Ukraine, look at Inflation destroying the World. NONE OF THIS HAPPENED WHILE I WAS PRESIDENT!”

His narrative leaves out key events, including Iran’s shelling of U.S. military forces stationed in Iraq and the pandemic-driven economic collapse of his final year in office. But Mr. Trump’s politics have always been impressionistic, and the events of recent days are helping his cause.

Israel is nearing all-out war with its biggest regional adversary, Iran.

And the Biden administration now appears incapable of restraining Mr. Netanyahu, who got virtually everything he wanted from Mr. Trump when he was in the White House and is likely to relish his return to power.

Lara Friedman, president of the Foundation for Middle East Peace, said that Ms. Harris seemed to have just hunkered down, waiting for Election Day before making any affirmative effort to change the course of events in the Middle East and pressure Mr. Netanyahu to de-escalate.

It isn’t working — politically or diplomatically.

“She was in a bind from the beginning,” Ms. Friedman said. “If she gave an inch” toward criticizing the Israeli government, “she would be framed as anti-Israel or even antisemitic. Even if she doesn’t give an inch, she’s still being framed as anti-Israel or antisemitic.”

“So maybe it would be better to conceptualize and stand behind a defensible policy” in the region, Ms. Friedman added.

Ms. Harris’s bind is only growing worse. The anger that Palestinian Americans were feeling toward the administration — especially in the key swing state of Michigan — has now been joined by anger from Lebanese Americans, also concentrated in Michigan, who are decrying the indiscriminate bombing of their homeland.

Attila Somfalvi, an independent political analyst in Israel, said on Wednesday that Mr. Netanyahu actually had more political space for a diplomatic resolution of the tensions. He has expanded his government beyond the narrow, far-right coalition that put him back into power, and the killing of Hezbollah’s leader, Hassan Nasrallah, has increased his popularity.

“There’s a feeling of strength again; people are saying, ‘Look, the magician is back,” Mr. Somfalvi said.

But for years, going back to the presidency of Barack Obama, Mr. Netanyahu has cultivated the belief among his supporters that the Democrats are the enemy, weak supporters of Israel at best, treacherous at worst. And now, with the Israeli right sensing a possible return of Mr. Trump, Mr. Netanyahu has no political incentive to help Ms. Harris.

“It’s pretty clear where the prime minister stands,” Mr. Somfalvi said. “All those fans of Netanyahu are very pro-Trump. It doesn’t matter what Biden and Harris have done over the last year. They say they need Trump.”

Earlier this year, that was not clear. Dennis B. Ross, a former presidential envoy to the Middle East, mused in an interview in March that Mr. Netanyahu might — just might — want the peace accord with Saudi Arabia that the Biden administration was trying to broker as his legacy, instead of the carnage of Hamas’s Oct. 7 attack on Israel. To attain that, he would have to accept a cease-fire in Gaza and a resumption of talks on autonomy for the Palestinians.

“A normalization deal with Saudi Arabia would serve both men,” he said of Mr. Biden and Mr. Netanyahu, while conceding, “the longer this goes on, given the political calendar, the less chance this can happen.”

That political calendar is now spent. Ms. Harris is likely to use the growing crisis in the Middle East to look resolute and presidential, as she did on Tuesday when she described joining the president and his national security team in the White House Situation Room to watch Iran’s missile attack on Israel unfold.

“Israel, with our assistance, was able to defeat this attack,” she declared. “Our joint defenses have been effective, and this operation and successful cooperation saved many innocent lives.”

With an uncertain season of Jewish High Holy Days beginning Wednesday night, with the first anniversary of the Hamas massacre of Israelis arriving on Monday, and with early voting already underway, Mr. Trump and Mr. Vance will take every opportunity to lay conflict at the feet of the Democrats.

“Donald Trump consistently made the world more secure,” Mr. Vance said in the debate. “When did Iran and Hamas and their proxies attack Israel? It was during the administration of Kamala Harris.”

Nevertheless, on the debate stage, Senator JD Vance of Ohio, Donald J. Trump’s running mate, wholeheartedly agreed with Gov. Tim Walz of Minnesota, the running mate of Vice President Kamala Harris, that shortages of affordable child care are a crisis for American families, and that the federal government should provide cash payments to parents.

“A lot of us care about this issue,” Mr. Vance said. He deftly used the line of questioning to rebut the image of him that has been painted by critics in recent months, as a right-wing scold with dated views on women and motherhood.

“I’m married to a beautiful woman who is an incredible mother to our three beautiful kids, but is also a very, very brilliant corporate litigator,” he said. “A lot of young women would like to go back to work immediately. Some would like to spend a little time home with the kids. Some would like to spend longer at home with the kids. We should have a family care model that makes choice possible.”

In sketching out his beliefs on child care, Mr. Vance sounded more like the moderate Republican he was perceived to be before he became so closely allied with Mr. Trump and the very-online right. He has long been loosely affiliated with a group of conservative intellectuals who have pushed the Republican Party to embrace government spending on child care and cash benefits, in part to encourage parents to have more children as access to abortion has become more limited.

At the debate, he argued that one way to bring down costs for child care was to allow the federal government to subsidize the informal care that takes place at home or outside of child-care centers.

There were still important differences between his position and how Democrats talk about the issue. Mr. Vance’s rhetoric on choice in child care is, in part, a reference to making it easier for parents — particularly mothers — to stay home with their children. Democrats tend to talk about child-care benefits as gender-neutral and as a crucial way to get more parents into the work force.

The morning after the debate, Oren Cass, a Republican who has been pushing for the party to embrace more generous child-care benefits, sounded elated. He is a former adviser to Mitt Romney and the founder of American Compass, a think tank trying to shift Republican social policy to become more populist.

“Outside of the highly educated, upper-income segment, the overwhelming majority of parents prefer either a stay-at-home parent or informal care over the commercial or government day care option,” he said.

“The only way to help people arrange the lives they want is to give people the resources directly,” he added.

Mr. Cass said he viewed the vice-presidential debate as a significant moment of change in national politics that signaled the potential for bipartisan cooperation on family policy in the coming years.

“Generational shifts are inevitable,” he said, noting Mr. Vance’s age — 40. “This is what conservatism will be.”

Of course, during the debate, Mr. Vance melded his instincts on child care with a hefty dose of Trumpism. He repeated the former president’s claim that tariffs on imports would raise so much money that paying for federal child benefits would be a breeze. Economists are dubious, and Mr. Walz pointed out that tariffs would raise the cost of goods for American households, potentially offsetting gains from more generous child benefits.

Mr. Walz promoted the universal paid family leave program he signed into law in Minnesota, which would be funded by a payroll tax shared between workers and employers. On child care, he gestured, albeit a bit vaguely, toward the fact that the business model is, essentially, broken.

The core problem in the sector is that the fees most parents can afford to pay do not cover the cost of doing business for providers, with money left over for profit. And one reason tuition at American child-care centers is so burdensome is that unlike most other developed nations, the U.S. government generally does not subsidize the cost. That has put care providers among the lowest-paid workers in the American economy.

“You can’t expect the most important people in our lives to take care of our children or our parents to get paid the least amount of money,” Mr. Walz said.

Julie Kashen, a child-care expert at the liberal Century Foundation, a think tank, said that as governor of Minnesota, Mr. Walz “has the receipts” showing he actually created more generous family benefits.

“Vance’s perspective has been, ‘Just ask grandma, just ask an aunt,’” she said. “The reality is most families have already tried that, and it’s not enough. Grandparents and aunts are helping out. We still need a system that pays child-care educators better and is affordable for families.”

During the debate, Mr. Walz did not dwell on the Republican opposition to the Biden administration’s Build Back Better plan, which would have capped child-care tuition at 7 percent of income for all but the wealthiest families.

Nor did he take the opportunity to point out that Mr. Vance recently missed a Senate vote on expanding the child tax credit, which failed because of Republican opposition.

Instead, Mr. Walz said, “I don’t think Senator Vance and I are that far apart.”

On the Screen

The ad opens with images of smiling, hard-working people engaged in jobs often filled by immigrants from Latin America: operating a food truck, picking crops on a farm, working construction, serving coffee in a diner. The background music is light and airy.

The spot then transitions to a grainy clip of former President Donald J. Trump at a rally as disturbing images pop on and off the screen. Young children are seen sleeping in cages, evoking Mr. Trump’s family separation policy. Cheering Trump rally-goers in cowboy hats hold up signs that read “Mass Deportation Now!”

Then the screen brightens as Ms. Harris appears smiling in a crowd of children and adults. Her presence is followed by scenes of happy families, a young person graduating from college and more Americans hard at work.

The Script

Narrator

“Working people, including hard-working immigrants, are bringing our economy back. But while Trump threatens to separate families and weaken our economy, Kamala Harris’s balanced approach to immigration is keeping families together: by protecting our loved ones from deportation, providing a pathway to citizenship and work visas for Dreamers. With the Biden-Harris administration’s historic action, working people like us can continue to build a good life and strengthen our economy for generations to come.”

Accuracy

The ad makes several broad claims about the immigration policies of Mr. Trump and Ms. Harris that are largely accurate. Under the Trump administration, thousands of children were separated from their parents at the border, and the former president has not ruled out reinstating that policy if he wins in November. Nonpartisan economic studies have found that Mr. Trump’s promise to deport millions of people would contribute to slowing economic growth.

The ad also accurately describes executive actions signed by President Biden, including providing a pathway to citizenship for the undocumented spouses of U.S. citizens and allowing the undocumented young immigrants known as Dreamers to obtain employer-sponsored work visas.

The Takeaway

Ms. Harris’s stance on border security is hard-line for a Democrat, and the ad is clearly trying to emphasize the more immigration-friendly part of her platform. It makes no mention of her support for a Biden administration policy that has blocked a vast majority of asylum claims at the U.S.-Mexico border and allowed agents to turn people back quickly. Instead, the ad focuses on the efforts that she and Mr. Biden have made to protect undocumented immigrants in the United States.

The goal seems to be shoring up her support with Hispanic voters — among whom she is struggling compared with previous Democratic candidates — by contrasting her approach to immigration with Mr. Trump’s and reminding them of the threat he could pose to undocumented immigrants if he is elected.

Somos PAC and Priorities USA Action say they are using YouTube to reach Hispanic voters in the battleground states who are less likely to participate in elections. Digital platforms allow advertisers to target their ads to specific groups of people and areas.

Least catchy coinage. Mr. Vance, seemingly pioneering a new term of art, described the vice president as waving a “Kamala Harris open border wand.”

Bravest fashion choice. Mr. Vance’s patterned fuchsia tie.

Sharpest zinger. Mr. Walz, responding to Mr. Vance’s repeated efforts to parry questions about the Jan. 6 riots with claims that the Biden administration and social media companies censored free speech. “January 6 was not Facebook ads.”

Most blatant nonanswer. When asked by his opponent whether he accepted that Mr. Trump lost the election in 2020, Mr. Vance replied, “I am focused on the future.”

Most unfortunate gaffe. Mr. Walz, saying “I’ve become friends with school shooters.” (He was discussing meeting with victims of gun violence.)

Worst-prepared answer. Mr. Walz’s effort to explain why he has falsely said he was in Hong Kong during the Tiananmen Square protests. After a windup about his background, sports teams and trips to China, he said: “I’ve not been perfect. And I’m a knucklehead at times.” Pressed again to answer, he said: “All’s I said on this was, is I got there that summer and misspoke on this, so. I will just — That’s what I’ve said.”

Most eclectic coalition. Mr. Walz, describing the breadth of Vice President Kamala Harris’s support. Her fans, he noted, include everyone “from Bernie Sanders to Dick Cheney to Taylor Swift.”

Biggest walk-back of a Nazi comparison. Mr. Vance, reminded of the fact that he once wondered if his running mate could turn out to be “America’s Hitler,” responding with this: “I’ve been extremely open about the fact that I was wrong about Donald Trump.”

Proudest husband moment. Mr. Vance, talking about his wife, Usha: “I am married to a beautiful woman who is an incredible mother to our three beautiful kids but is also a very, very brilliant corporate litigator and I am so proud of her.”

Biggest vanishing act. President Biden, who was mentioned far fewer times than during the presidential debate last month. He was invoked by name just four times by Mr. Vance, and not once by Mr. Walz.

Loudest offstage Greek chorus. Former President Donald J. Trump, live-blogging the debate on Truth Social with dozens of posts, sometimes in all caps. “EVERYONE KNOWS I WOULD NOT SUPPORT A FEDERAL ABORTION BAN,” he wrote at one point.

Quickest to quote Scripture. Tim Walz, saying “I don’t talk about my faith a lot,” before paraphrasing the Gospel of Matthew. “To the least amongst us, you do unto me.”

Showiest show of compassion: Mr. Vance, empathizing with his opponent after Mr. Walz described an ordeal his son had experienced: “Tim, first of all, I didn’t know that your 17-year-old witnessed a shooting. And I’m sorry about that and I just want to say, Christ have mercy. It is — it is awful.”

Most condescending cutoff. Margaret Brennan, one of the two CBS moderators, cutting off Mr. Vance in an extended exchange about the asylum process and Haitian immigrants in Springfield, Ohio: “Thank you, Senator, for describing the legal process.”

Most distracted viewer. Writing on Truth Social, 95 minutes into the debate, Mr. Trump demanded an apology from CBS’s Lesley Stahl for her previous coverage of Mr. Biden’s son’s laptop. (Ms. Stahl was not part of Tuesday night’s debate.)

Most Midwestern flex. Mr. Walz, making 20 references to Minnesota.

Most Orwellian-sounding scenario. Norah O’Donnell, the other debate moderator, asking Mr. Vance — after Mr. Walz referred to a Project 2025 proposal to collect more data about abortions: “Will you create a federal pregnancy monitoring agency?”

Slipperiest spin. Mr. Vance, shifting from the pregnancy monitoring question to discuss abortion. “I want us as the Republican Party to be pro-family in the fullest sense of the word. I want us to support fertility treatments. I want us to make it easier for moms to afford to have babies. I want to make it easier for young families to afford a home so they can afford a place to raise that family. I think there’s so much we can do on the public-policy front just to give women more options.”

Most effective shush. Ms. Brennan, hushing the candidates during one particularly heated exchange over immigration. “Gentlemen, the audience can’t hear you,” she informed them, “because your mics are cut.”

“This is long, huh?” Grant Pitts, a senior who is president of the Parkside student government, said to a room full of students who groaned in agreement.

Debates between vice-presidential candidates are usually low-impact events, even if they can deliver a memorable moment once a decade or so, like Sarah Palin’s wink to the camera in 2008 or Lloyd Bentsen’s humbling of Dan Quayle in 1988.

Tuesday night did not deliver one of those moments, at least to students at three colleges in the closely contested swing states of Wisconsin and Georgia. Some students, jaded with politics altogether, seemed to have decided well before the debate that it would not be must-see TV. Many said they had already settled on a candidate, and that there was little either Mr. Vance or Mr. Walz could say to change their minds.

At the University of Wisconsin-Milwaukee, only a handful of people showed up for a watch party at the student union that had been advertised online and in the school newspaper well before Tuesday.

“No one around here seems to be into politics, and those who are probably made up their minds a long time ago,” said Jade Rahn, a 19-year-old sophomore who will be voting in her first presidential election in November. As she watched from a mostly empty student lounge where a table of snacks sat mostly untouched, Ms. Rahn said she has been leaning toward Mr. Trump because she believes he handled economic issues better.

And while she remains somewhat receptive to switching candidates, nothing she heard at the debate moved her much. “I’m open,” Ms. Rahn said, taking an occasional break from the debate to finish some homework. “But don’t think anything said during this debate will change my mind.”

Younger voters present a challenge for the campaigns of Vice President Kamala Harris and former President Donald J. Trump. Many say they are disillusioned by the negativity of American politics and doubt that any candidate can help put the country — and their lives — back on track. They came of age in an era when problems such as climate change and mass shootings overwhelmed many in their generation, and the American political system seemed unable to do anything to fix them.

Ethan Hightire, a 21-year-old senior at the University of Wisconsin-Milwaukee, said he was not even aware of the vice-presidential debate until a day ago. He came to watch with his classmates hoping to hear from the candidates themselves, instead of relying on a news media that he believes is not telling the full story.

“It’s hard to take a stance because most of the information online and in the news is biased,” Mr. Hightire said. “I think it’s better to hear directly from them.”

But even that may not be enough for Mr. Hightire to make a decision with confidence because, he said, “What they say may not be what they do.”

At Mercer University in Macon, Ga., the organizers of a nonpartisan watch party weren’t quite certain how many people would show up. Three weeks earlier, a watch party for the debate between Ms. Harris and Mr. Trump drew about 60 people. On Tuesday, the crowd ended up being quite a bit short of that.

Hannah Griffin, a 20-year-old premedical student who is studying biochemistry, said she yearned for an election where a vice-presidential debate would help decide her vote. But as she watched, she acknowledged that the volleys between Mr. Vance and Mr. Walz would do absolutely nothing to sway her in November.

“It is my hope that at some time in the future, we will have better candidates that aren’t Donald Trump and just so unbelievably horrible that, really, the only option, at least for me personally, is to vote for Kamala Harris,” Ms. Griffin said.

At Mercer’s student center, some paid more attention than others. And neither Mr. Vance nor Mr. Walz provoked much of a reaction from the room. With fall break looming, many students eyed the debate while doing homework or enjoying the free snacks.

For younger people who have yet to experience a presidential election as full-fledged, voting-age citizens, the debate on Tuesday offered something novel: a stage without Mr. Trump.

Ryan Rivera, a 20-year-old who works at a Target in the Phoenix area, was struck by how much Mr. Trump’s absence changed the dynamics — and felt almost pleasant. “Honestly, it’s refreshing to see two political candidates be genuinely respectful to each other,” said Mx. Rivera, who uses the/them pronouns. “We cling to the drama. It’s just nice to not have that.”

Even if some voters said they were putting a lot of weight on the vice-presidential debate, it was probably never likely to factor significantly in many minds.

The polls have remained relatively stable this year despite a torrent of history-making news that could have upended any other presidential race. These include the first criminal conviction of a former president, the late decision by a sitting president not to run for re-election and two assassination attempts against Mr. Trump.

Mr. Walz seemed to nod at one point to the fact that Americans had other things on their minds when he used his closing statement to jokingly thank “the folks who missed ‘Dancing with the Stars.’”

By the time candidates delivered their closing remarks, only two students remained at the Milwaukee watch party.

At the University of Wisconsin-Parkside, a small campus in the southeastern corner of the state with 3,200 undergraduates, the student body is more diverse than the state’s overall population. More than 35 percent of students are eligible for Pell Grants and nearly half are the first in their families to attend college. Maribel Muñoz, 18, a freshman, said she had cringed at Mr. Vance’s comments on immigration, especially when the topic of Haitian immigrants in Springfield, Ohio, was raised.

“I’m the granddaughter of two immigrants,” she said.

But as unappealing as she found Mr. Vance, she said she was not sure the Democratic ticket was a much better alternative.

“I’m not sure if I will vote,” Ms. Muñoz said.

Jack Healy and Oralandar Brand-Williams contributed reporting.

But when the debate turned, near its final frames, to the subject of the 2020 election, Mr. Vance faced a choice: He could validate, once more, Donald J. Trump’s relentless lies about his defeat four years ago. Or he could try something else in the spirit of moving forward.

It did not seem like a difficult decision for him.

“What President Trump has said is that there were problems,” Mr. Vance said when asked about his own past assertion that he would not have certified the 2020 election. “We should fight about those issues, debate those issues, peacefully in the public square. And that’s all I’ve said. And that’s all that Donald Trump has said.”

His debate opponent, Tim Walz, stared at him, unblinking, and then looked down at his lectern.

“Remember,” Mr. Vance said of Mr. Trump, “he said that on January the 6th, the protesters ought to protest peacefully. And on January the 20th, what happened? Joe Biden became the president. Donald Trump left the White House.”

This accounting was short a few details — the violence, the deaths and injuries, the alleged criminal scheming, the “Hang Mike Pence” of it all.

Mr. Vance pivoted jarringly to the subject of censorship. Mr. Walz glanced up at the camera, silent, like a television character breaking the fourth wall.

“Well, I’ve enjoyed tonight’s debate,” Mr. Walz began when it was his turn again, assessing an evening that was sometimes wobbly for him. He was about to enjoy it more.

For all their occasional paeans to civility on Tuesday, this was the moment that crystallized an unshakable truth about this election: One side still refuses to acknowledge the truth about the last one — the persistent falsehood that has come to define so much of the era’s fragile and rampaging politics.

“We need to tell the story,” Mr. Walz said. “I mean, he lost this election and he said he didn’t.”

Mr. Walz often speaks with a how’d-I-even-get-here feint toward political humility, as if he intends to decorate the Naval Observatory in Carhartt camo and has not given much thought to other plans.

At his most effective, he is a kind of Labrador retriever of a communicator: affable, game, just happy to be there — but liable to tilt his head in performative confusion when something sounds off to him.

On Tuesday, after some dissembling episodes earlier in the debate — particularly concerning past misstatements about his proximity to the Tiananmen Square massacre as a young man — Mr. Walz made a bid for the high ground, summoning more compelling details from his biography.

He was a teacher, he noted, and a football coach.

“I worked with kids long enough to know,” he said, “sometimes you really want to win.”

But Republicans like Mr. Trump were already laying the groundwork to contest the current election, he continued, and perhaps even to imprison their political opponents.

“A president’s words matter,” Mr. Walz said, punctuating his own. “A president’s words matter. People hear that.”

Mr. Vance had heard enough.

“It’s really rich,” he said, chopping the air with his hands, “for Democratic leaders to say that Donald Trump is a unique threat to democracy when he peacefully gave over power on January the 20th.”

He moved to equate past Democratic complaints about election outcomes, including invocations of Russian interference in 2016 through Facebook ads and other means, with the response in 2020.

“Jan. 6 was not Facebook ads,” Mr. Walz shot back, as Mr. Vance smiled slightly.

Mr. Walz had a question for his counterpart.

“He is still saying he didn’t lose the election,” Mr. Walz said of Mr. Trump, turning grandly to Mr. Vance. “Did he lose the 2020 election?”

“Tim,” Mr. Vance replied, “I’m focused on the future.” He swerved to a point about Covid and censorship.

“That,” Mr. Walz said, “is a damning non-answer.”

There was a reason, he added, that Mr. Pence was not on the stage as Mr. Trump’s running mate anymore.

And it was worth asking, he said, what that could tell viewers about Mr. Vance.

“America, I think you’ve got a really clear choice,” Mr. Walz said, his eyes getting bigger, “of who’s going to honor that democracy and who’s going to honor Donald Trump.”

Mr. Walz tried to dismiss the misstatement as insignificant, saying he sometimes gets “caught up in the rhetoric.” He then pivoted to assert that his work as a teacher, congressman and governor was evidence that his community trusted his record despite his missteps.

Mr. Walz has long said that he was in Hong Kong on June 4, 1989, the day that Chinese soldiers killed hundreds of protesters in Tiananmen Square. He has said that he entered mainland China shortly after, even as others chose not to travel there, because he wanted to forge ahead with his yearlong teaching stint in the country — framing it as a courageous act.

“My thinking at the time was, what a golden opportunity to go tell, you know, how it was,” Mr. Walz told the podcast “Pod Save America” in February. “And I did have a lot of freedom to do that. Taught American history and could tell the story.”

But Mr. Walz was not yet in Hong Kong. He was in Nebraska until that August, according to news reports from the time. The timeline of his trip was first questioned by Minnesota Public Radio on Monday. His campaign did not provide an explanation.

Even as he acknowledged the misstatements at Tuesday’s debate, Mr. Walz again appeared to muddle the timeline: “I was in Hong Kong and China, during the democracy protests, went in. And from that I learned a lot about what needed to be in governance.”

There were rallies in Hong Kong to support the pro-democracy protesters in China, even after the military crackdown. But Mr. Walz appears to have arrived after the large protests in the People’s Republic that people commonly think of as the pro-democracy protests.

Republicans have pounced on the issue, pointing to it as another of a series of exaggerations and misstatements Mr. Walz has made, both large and small, that have surfaced since he was named Vice President Kamala Harris’s running mate.

Those include a comment he made in 2018 about “weapons of war that I carried in war” as a member of the National Guard, when he never served in combat. He has also implied that he and his wife used in vitro fertilization to start their family. In fact, the couple used a different treatment, intrauterine insemination.

Edward Wong contributed reporting from Washington.