EAU CLAIRE, Wis. – Maybe it's the talk of fat shaming, or adultery, or sexual assault, or bans on Muslims and walls to keep out Mexicans. But Brent Wathke is having a rough time teaching this presidential campaign to his seventh-graders.

He is not planning to show his students the third presidential debate on Wednesday; he feels the debates have long ago crossed over into inappropriate. Television ads, particularly the ones from Hillary Clinton's campaign that heavily quote Donald Trump, are filled with misogynistic comments. Even political cartoons, which Wathke would have liked to use to teach his students about the delicate art of satire, are too risqué.

"It is a total mess," said Wathke, 33, sitting in his classroom at DeLong Middle School one morning last week, near a dry-erase board where he had scrawled "25 Days to Election" in a red marker. "Honestly, I just can't wait until it's over."

Wathke is one of countless teachers across the country who have anguished over the dark and sometimes shocking tone of the presidential campaign. Like many, he has searched for ways to talk about it in class. Some teachers are planning mock debates before the election; others, like Wathke, fear that the format could invite students to spout insulting rhetoric.

His students, most of whom are 12 years old, have been buzzing with talk of the campaign all year. The first group of students poured into the classroom just before 7:30 a.m., clutching notebooks and binders, and sat in desks arranged in circles.

"I believe if Trump is elected, it's going to be like 'The Hunger Games,' " said Payton Foy, prompting nervous giggles around the room. "I'm not trying to be mean to Trump. I just really believe that."

Another student piped up, saying she had watched the second presidential debate the night before. "And?" Wathke asked.

"It was bad," she said.

He grimaced. "I don't want to shield you guys from that, but there are some things in there that just aren't appropriate for school," he said. "So we're going to stick to the issues today."

Wathke has spent down time on evenings and weekends worrying about the effect of the campaign on his seventh-graders. In Chicago on a recent weekend to run his 13th marathon (he is also one of the school's cross-country coaches), he read the news that an "Access Hollywood" microphone had captured Trump on a bus bragging about groping women. There was not time for Wathke to consider the political implications; his mind raced ahead to the coming Monday morning.

"All I'm thinking is, 'How am I going to approach this?' " he said.

His students said they have also wondered what they were allowed to say about the campaign in class. "We self-censor a lot," said Connor Felton, 12. "I think if you repeat some stuff that Trump says, you could get sent down to the principal's office. Maybe even expelled."

Here in Eau Claire, a retail and manufacturing hub of 68,000 people in this crucial swing state, children and teenagers are most likely exposed to more political messages than most of their peers in other states.

Campaign ads and yard signs are everywhere; both Clinton and Trump have held rallies in town this year. Wathke said he gets nervous when he hears that his students are planning to attend rallies. At Trump's rallies, the candidate has used foul language and mimicked a reporter with a physical disability. His supporters often wear T-shirts with crude sexual slogans referring to Clinton.

In Wathke's own classroom, he has aimed for civility. A native of Eau Claire with a polite manner, he was once a student at DeLong, where he now teaches in the same classroom where he learned social studies. Now, those walls are plastered with campaign signs, many years or decades old: Bush/Quayle '92, Dole for President, Irish Americans for Kerry/Edwards.

This semester, Wathke and his five social studies classes have been talking about politics — delicately — since August. He is teaching his seventh-graders about the three branches of government, how democracies work and the differences between Republicans and Democrats.

Since he feels that free-form debate is risky, he prepared his class to discuss the campaign using "Socratic circles," separating students into small groups. The students were armed with work sheets, filled out before class, answering questions he had posed. What are the most important issues facing the country? Where do the candidates stand? Which candidate would be a better president?

At the beginning of one discussion, he laid out a warning. "We're going to be talking about some topics today that can get a little tricky today and a little heated," he said. "But we want to make sure we're being respectful of one another and we're not hurting feelings. Remember when we watched some of that debate? And there was one thing that was the most annoying thing? The interruptions. We don't want interruptions today."

At the end of one discussion, Wathke looked relieved. "I want to say that you did pretty darn good," he said. "You avoided the memes you see on social media. You stuck to the issues."

His approach: Tread lightly and let the students move their own discussion. If the conversation in class turns inappropriate, step in.

"The campaign is ruining a lot of classes," Wathke said. "You have kids saying, 'We need to have a wall to keep Mexicans out.' Well, what do you do if you have kids who are Mexican in the class?"

That kind of conversation in the campaign arouses anger in some of his students. "Racial profiling is going way back in time," said Donna Xiong, 12. "I don't think it's OK at all. If I got kicked out of a store for being Asian or for my skin tone, that's not right."

Gabriel Morken, 12, said he believed the Black Lives Matter movement was one of the most important issues. "Donald Trump thinks it's really bad," he said. "Hillary wants everybody to be equal and stuff."

DeLong has a history of holding mock elections, and for as long as anybody there can remember, maybe 20 years or more, the students have chosen the candidate who later won the presidential election. This year, the mock election will be on Nov. 8.

After a group of his students filed out, Wathke said he never knows quite how much campaign news they have absorbed on YouTube and Snapchat, where they spend so much time. He assumes they see everything.

A few weeks back, he decided to show them a Romney-Obama debate from 2012, for a contrast. "I thought I'd show them what a typical debate would be like," he said. "The first response was, 'That's kind of boring.' "