New York City has never been immune to heated education fights, but in recent months they have taken on a new level of vitriol and aggression, and expanded to a broader menu of divisive issues.

The battles reflect the nation’s growing political divide even in this deep blue city, as parents layer old debates — how issues of race and discrimination are taught in schools, for example — over newer ones, such as the role of transgender students in sports and how schools should address the Israel-Hamas war.

Parents have shouted over each other, called each other bigots and made formal complaints about behavior at meetings traditionally focused on issues like school improvements and student achievement. Some parents have filed police reports against each other for harassment. One woman said she was mailed a parcel with feces inside.

The battlegrounds have also multiplied, from a few notoriously quarrelsome parent councils to traditionally peaceful spots around the city.

In other districts around the country, changes in school board policy can transform what happens in classrooms. In New York City, the parent councils where many of the fights are occurring — and which represent the public school system’s 32 districts — have little power, because the mayor controls the schools.

But the new battles — about issues that don’t always break cleanly along party lines — have created a challenge for an administration trying to manage what is perhaps the nation’s most diverse school district.

The city’s schools chancellor, David C. Banks, has previously shown a willingness to listen to families’ worries over the direction of the system, including its handling of desegregation at elite schools. But the tenor of the new debates has families demanding that officials do more to intervene.

As the fighting continues, Mr. Banks suggested last week that city education leaders would soon have more to say about “the nonsense we’ve seen.”

“It is the thing that in this role as chancellor I find most disappointing,” he said. “Adults behaving badly.”

Perhaps nowhere are tensions more evident than in District 2, a sprawling and diverse section of the system weaving through the heart of Manhattan — from the West Village and Hell’s Kitchen to the Upper East Side.

The district’s parent meetings have always been contentious, but families there had mainly sparred over efforts to loosen admissions at selective schools. Recently, though, they have argued over books with more diverse story lines and whether to disavow the right-wing advocacy group Moms for Liberty, among other issues.

And last month, parents there passed a proposal asking the city’s Department of Education to review its gender guidelines, which currently allow students to participate on sports teams based on their gender identities, regardless of the sex they were assigned at birth.

The effort was led in part by Maud Maron, one especially vocal parent leader whose rhetoric has come under fire from school officials. At a remarkably tense March meeting, held in person and online, she and other parents said that the current policies presented “challenges to youth athletes and coaches,” and that they failed to consider the “well-being of girls.”

During the meeting, parents attending remotely argued over whether their children would be unsafe if transgender athletes joined girls’ teams. Several elected officials called the discussion “disgraceful.” Mr. Banks later asked, “Won’t you just leave the kids alone?”

The proposal, a nonbinding recommendation to officials, ultimately passed in an 8-3 vote. In a post on X, Moms for Liberty called the vote “a huge step for NYC!” This year the organization held its first major local event, which some District 2 parent leaders attended as panelists, and the group now has a small chapter in Queens.

It is unclear how much the parent council represents broader views within District 2. The council’s members recently won their spots with several hundred votes, and the district has some 20,000 eligible parent voters.

Still, Mark Levine, the Manhattan borough president and a progressive Democrat, said “the MAGA movement has come to Manhattan.”

Other neighborhoods are also becoming battlefronts.

In District 14 — which includes Williamsburg, Brooklyn — some parent leaders have vocally called for a cease-fire in Gaza, and say they have faced threats for their stances. At the same time, other parents filed a federal lawsuit last week over the council’s policies, arguing that those who “dissent from official orthodoxy” face unfair scrutiny from school officials.

Even students have joined the battles at times. At the city’s most prestigious high school, teenagers launched a campaign to expel Ms. Maron from their school leadership team for “deeply hurtful” rhetoric toward minority groups on social media.

The safety of the “most vulnerable students is at stake,” they wrote. Ms. Maron did not return a request for comment.

The conflicts are arising after some parents formally organized in recent years over their anger at a proposal to overhaul admissions at the city’s specialized high schools. When moderate or conservative parents feel like their concerns are not being heard in more progressive places, experts said, the messages of a group like Moms for Liberty can resonate.

Rebecca Jacobsen, an education policy professor at Michigan State University, said that the increasingly charged environments could reflect a lasting change. “It is not going back to the way it was,” she said, referring to the national landscape.

Others who study political fights in education pointed to school closures during the coronavirus pandemic. “They galvanized a certain kind of conservatism in New York City which we hadn’t seen in a while,” said Natalia Mehlman Petrzela, an associate professor of history at the New School.

Now, she added, “it’s taken hold in other issues.”

In recent months, Mr. Banks, the schools chancellor, has begun to criticize parents for their behavior more often.

But the fighting has prompted questions over how far officials should go. The president of the city’s teachers’ union, Michael Mulgrew, wants them to do more. He said in a recent letter that some parent leaders had used their platforms to “denigrate and endanger students,” raising concerns that children could suffer.

Still, Kenita Lloyd, a top school official overseeing family engagement, said at a press briefing last week that removing elected parent leaders could set a “dangerous precedent.”

But some parents remain disappointed. “The adults in the room at the Department of Education really need to step in,” said Gavin Healy, a parent leader in District 2.

In New York, several recent chancellors have encouraged schools to expand the type of teaching — on issues like identity and discrimination — that some other cities have restricted. That too appears to be drawing fresh dissent in at least one neighborhood.

The news site Gothamist reported last month that books on topics like Native American history and the Black Panther superhero were found in the trash at a Staten Island elementary school. Some were labeled with notes, including “Not approved. Discusses dad being transgender. Teenage girls having a crush on another girl in class.”

At the recent unveiling of new lessons on the African diaspora, Mr. Banks said that the teaching of Black history was “under attack all across America.” He said that students would be exposed to diverse stories “whether folks like it or not.”

As the State Legislature considers whether to renew mayoral control of the city’s public schools, the abstract parent fights could have more resonance. Some want state lawmakers to give elected school boards power to make real policy.

Brad Hoylman-Sigal, a Democratic state senator who represents much of Manhattan’s West Side, said “we need to be mindful of how” both school boards and parent councils “can be hijacked.”

Still, experts note that voter turnout — which sits at around 2 percent in parent council elections — would likely rise if the stakes were higher.

Whatever lawmakers decide, John Rogers, a U.C.L.A. professor who has studied education fights, said national political conflict over school issues was likely to grow in the lead-up to the presidential election.

“I think it’s only going to be heightened in the months to come,” he said.