With less than a month before Election Day, the candidates for governor of New Jersey faced off on Wednesday in a final debate that showcased stark differences in how they plan to lead the state.

The hourlong debate also featured flash points over the Trump administration’s release of one candidate’s military records and its decision to withhold $16 billion for construction of a new commuter rail tunnel under the Hudson River that is vital to New Jersey’s economy.

Only New Jersey and Virginia hold races for governor this year, and both are considered early tests of voter attitudes toward President Trump a year before congressional races that will determine the balance of power in Washington. More than 200,000 New Jersey voters have already cast ballots by mail. And television ads are omnipresent.

Democrats have branded Jack Ciattarelli, a Trump-endorsed Republican running for governor for the third time, the “Trump of Trenton” in ads.

Mr. Ciattarelli has countered by depicting his opponent, Representative Mikie Sherrill, as an extension of the state’s Democratic governor, Philip D. Murphy, in ads that describe her as “Murphy 2.0.”

Turnout will be critical. Four years ago, Republicans angered by pandemic-related mask and vaccine policies flocked to the polls, and Mr. Ciattarelli came within 3 points of beating Mr. Murphy in his second time running for governor. Registered Democrats outnumber Republicans in New Jersey by roughly 850,000 voters. Still, Mr. Trump’s stronger-than-expected showing in November in New Jersey has led Mr. Ciattarelli to make direct appeals to Black and Latino voters in traditional Democratic strongholds.

Each of the candidates is now focused on energizing their base ahead of the Nov. 4 election and persuading the state’s 2.3 million voters who are not affiliated with either party of the merits of their platform.

These were some of the key moments in Wednesday’s debate:

Ms. Sherrill’s Military Records

The race for governor was jolted in recent weeks by twin revelations.

First, that the Trump administration had released Ms. Sherrill’s full personnel record, largely unredacted, disclosing her Social Security number and performance evaluations. Then, in the throes of a cheating scandal at the Naval Academy, that Ms. Sherrill had been barred from attending commencement exercises in 1994.

Unsurprisingly, the episode took center stage at Wednesday’s debate.

Ms. Sherrill, a former Navy helicopter pilot, has made her military service a central component of her campaign. She has noted that two of her four children are enrolled at her alma mater, the U.S. Naval Academy, and that Mr. Ciattarelli did not serve in the military.

Asked about the cheating scandal by the moderators, Ms. Sherrill stated that she was not allowed to participate in the ceremony because she did not “turn in” classmates. “I didn’t turn in some of my classmates, so I didn’t walk at graduation, because I come from an incredibly accountable place,” Ms. Sherrill said, reiterating an explanation she has given before.

She quickly pivoted to an attack on Mr. Ciattarelli. “Here’s what I think: I think what really demands an answer is why my opponent still won’t take accountability for the release of those records.”

Mr. Ciattarelli was immediate with a retort. “At the last debate, Mikie said that she was the most transparent gubernatorial candidate of all time,” he said. “If she’s so transparent, then approve the release of her disciplinary records at the Naval Academy so we can know why it is that she was punished.”

The records disclosed by the Trump administration did not include information about the cheating scandal. And Mr. Ciattarelli has said that Ms. Sherrill should share any disciplinary records that support her explanation.

Her campaign has previously said it would not “release anything to Jack’s campaign in his clear attempt to smear a veteran.”

Mr. Ciattarelli’s Support for President Trump

In 2015, as Mr. Trump was campaigning for president, Mr. Ciattarelli — then a state assemblyman preparing to run for governor for the first time — was unsparing in his criticism of Mr. Trump, calling him a charlatan who was “not fit to be president.”

Mr. Ciattarelli has since fully embraced Mr. Trump, earning the president’s full-throated endorsement and a promise that he was “100% (PLUS!)” MAGA. That’s put him in a potentially difficult spot in New Jersey, where a recent poll showed that 55 percent of residents disapproved of the way Mr. Trump is handling his job as president.

This vulnerability was laid bare last week when Mr. Trump suddenly froze funding for the new commuter rail tunnel known as Gateway. On Wednesday night Mr. Ciattarelli refused, as he has in the past, to criticize the president.

Ms. Sherrill challenged him during the debate on what she said was his refusal to stand up to the president to protect New Jersey residents.

“Jack won’t say one cross word about the president,” she said.

Mr. Ciattarelli said it was wise to have a relationship with the president, and he noted that during the pandemic Mr. Murphy went to Washington to ask Mr. Trump to supply ventilators.

“In times of need, it’s best to have a relationship with whoever is in the White House,” Mr. Ciattarelli said.

Taxes

New Jersey has some of the nation’s highest property and business taxes, topics that were on the minds of both candidates before the moderators even began questioning.

In their opening statements, both Mr. Ciattarelli and Ms. Sherrill offered brief pitches on how to address the affordability crisis. And while answering the first question, the candidates tussled over property taxes and the Trump administration’s signature law, the One Big Beautiful Bill Act.

Mr. Ciattarelli celebrated the bill for raising the federal deduction for state and local taxes to $40,000 from $10,000 (a limit that the first Trump administration put in place). And he said he would look to revamp the school funding formula, a policy goal of Mr. Ciattarelli’s since he first ran for office in 2017.

But Ms. Sherrill argued that the Trump administration’s signature bill “would undermine the ability to deduct almost 30 billion in taxes from New Jerseyans.” She again pivoted to a common attack line from her campaign, claiming that Mr. Ciattarelli wants to raise taxes on New Jersey.

Mr. Ciattarelli glared at Ms. Sherrill, and swiftly called her line “a lie.”

“It’s not true,” Mr. Ciattarelli said. “We’re not raising any taxes in New Jersey.”

Political Violence

A question about political violence was met instead with a combative tone from Mr. Ciattarelli.

He said he applauded Ms. Sherrill’s decision to leave the campaign trail to go to Washington to vote for a resolution honoring Charlie Kirk, the conservative leader who was assassinated last month. But, Mr. Ciattarelli said: “When she came back to New Jersey and caught hell from the left, she issued a statement condemning Charlie Kirk, calling him a misogynist and a racist.”

He added, “The two things are inconsistent to me.”

Ms. Sherrill, who had previously spoken about the “horrific” murder of a judge in New Jersey and the specter of political violence, spoke about the importance of free speech, before responding to her opponent.

“That resolution was a resolution standing up for free speech and standing against political violence, and I do feel very strongly about that,” she said, referring to her vote in Washington. “I also feel very strongly that despite the fact that Charlie Kirk had a right to say a lot of things, I deeply disagreed with him. In fact, when I asked my opponent if he could disagree with Charlie Kirk saying Martin Luther King was a bad guy, or that women should be subservient to their husbands, he could not.”

Immigration

Mr. Ciattarelli has said that he would repeal a state policy that limits the amount of voluntary assistance that local law enforcement officers can provide to federal authorities enforcing civil immigration laws.

“I’ll secure New Jersey by us not being a sanctuary state, nor having sanctuary cities,” Mr. Ciattarelli said.

He also said that undocumented residents should have a “pathway to recognition.”

Ms. Sherrill shot back, saying that “that’s not really a thing.”

“That doesn’t confer any status,” she added, noting that she supports “comprehensive immigration reform.”

She said that as a former federal prosecutor she was the “only person on the stage who has prosecuted a violent criminal who has been deported.”

Mr. Ciattarelli later questioned the yearlong duration of her employment as an assistant U.S. attorney in the District of New Jersey and suggested that most cases she handled were plea deals.