For more than two years, Tefft had been arguing with 30-year-old Peter, hoping he'd stop embracing the racist and sexist "garbage" he'd found online. Now, Tefft had seen undeniable proof of what his youngest child had come to align himself with. As a father, what was he supposed to say?
"I told him his actions are not acceptable," Pearce Tefft recalled yesterday. And "I told him what I was going to do."
What he was going to do was publish a letter in Fargo's local newspaper, the Forum. He was going to openly denounce his son's beliefs. It would appear the next morning.
"I have shared my home and hearth with friends and acquaintances of every race, gender and creed," Tefft wrote in that letter. "I have taught all of my children that all men and women are created equal. That we must love each other all the same.
"Evidently," the letter continued, "Peter has chosen to unlearn these lessons."
It was once easy to assume that if people were openly racist, they had probably learned those views at home, from the people who had raised them.
But today, the teachings of unvarnished, unapologetic racism are accessible to anyone with an Internet connection.
Just as the web has helped radicalise Muslims and spread conspiracy theories, its infinite depths have also provided a breeding ground for white supremacists, Nazi sympathisers and the phony science that purports to back their beliefs.
A person so inclined can digest and internalise it all, drastically altering their views without ever meeting the people persuading them to do so.
When reporters told the mother of James Alex Fields that her 20-year-old son had been arrested for allegedly ploughing his car into counterprotesters in Charlottesville, she seemed genuinely surprised to find out what type of rally her son had been attending while she watched his cat back in Ohio.
"I didn't know it was white supremacists," Samantha Bloom said. She mentioned that her son once had an African-American friend.
Meanwhile, Internet sleuths were sifting through photos of other protesters at the "Unite the Right" rally, determined to identify their names, ages, hometowns and employers.
With each name uncovered came the possibility that somewhere, another parent was finding out for the first time that their child was an avowed racist.
And for those who already knew about their offspring's beliefs - well, now everyone else knows, too, and many won't hesitate to show their disgust. Like Tefft, these parents will be presented with a decision perhaps unique to the Internet age: What are you supposed to do when you find out your kid sympathises with Nazis?
Love them unconditionally, knowing you will feel the wrath of public backlash? Or speak out against your child publicly and risk losing your chance of getting them to change their ways?
You could ask Sherry Spencer, the mother of Richard Spencer.
Her son rose to prominence at a conference shortly after the 2016 election, when he ended a speech by calling out "Hail Trump! Hail our people! Hail victory!" as audience members raised their arms in a Nazi salute. He has become a leader of the alt-right movement, which calls for a whites-only state.
In the Spencer family's hometown, Whitefish, Montana, community members demanded that Sherry Spencer publicly disavow her son's beliefs. A real estate agent sent her a statement, already drafted and ready to go, in which she could acknowledge that she recognised that her son's presence in Whitefish was "hurting the people here."
Sherry Spencer didn't go through with it. Instead, she wrote a blog post claiming that the real estate agent was threatening her.
"Whatever you think about my son's ideas - they are, after all, ideas," she wrote, "in what moral universe is it right for the 'sins' of the son to be visited upon the mother?"
The answer, as Tefft has learned, seems to be: this universe.
His family members, especially Peter's mother, have been inundated with social-media messages and phone calls from people who assume they share or condone his opinions.
The backlash began when Peter started discussing his beliefs locally, but it snowballed this past weekend, when the Twitter account @YesYoureRacist posted a photo of Peter at the Charlottesville rally with the caption, "This charming Nazi is Pete Tefft of Fargo, ND."
Peter Tefft, who identifies as a "pro-white activist" online, did not respond to requests for comment for this article.
His father said the messages the family received because of "guilt by association" were so vile, he wouldn't repeat them. He cancelled his landline phone service.
"Why do they automatically think he learned it at home?" he asked. "He didn't learn this at home. . . . He's 30 years old. And he never did any of this stuff the first 28 years."
Tefft first learned of his son's changing views a few years ago, when Peter encouraged him to check out the websites he had been reading.
A lifelong independent, Tefft had always urged his six children to try to understand the world from multiple viewpoints. So he was unsurprised that his son was seeking out knowledge. But what he found on the sites Peter mentioned was nothing like the values he tried to instill in his churchgoing, military-serving family.
"I point out to him where they are wrong, and other sources, and he just dismisses it, like, 'No, no, no, you're not learning this stuff right, Dad,' " Tefft remembered. "I tell him, 'Jews are white,' and he says, 'No, they're not.' . . . He's also a Holocaust denier. That's ridiculous."
They argued about the evidence. They argued about why the elder Tefft, his parents, his brother and two of Peter's older siblings all served in the military - to fight for "a country where we respect each other," as the father puts it.
They argued about the equality of women, and this might have been the part that most troubled the father about his son.
"It's just idiocy when he starts to compare women and whatnot," he said.
He said he told Peter: "Good lord. You got four aunts, four sisters - what's the matter with you? One of them beat you in basketball, and at least three of the other ones, if not all four, are smarter than you."
"That's half a joke, because I treat them all equal," Tefft explained. "But I'm trying to get the point across to him."
It has not yet worked. "It's like banging my head against the wall," Tefft said. "It's like he has blinders on, and I don't know where they came from."
When Peter returned to North Dakota from Charlottesville, Tefft explained that from then on, his son would no longer be welcome at family gatherings. He said that he promised he would always talk to him but that other family members had vowed to turn their backs or leave if Peter ever showed up. They were too angry about the hate they've had to endure because of the hate he has spread.
Tefft said his son listened to him and didn't become upset.
He went to sleep that night hoping the cruel messages to his family would subside after his letter was published in the morning. And hoping, still, that his son might come around.
In his closing words in the letter, Tefft recalled a sick joke his son once told: "The thing about us fascists is, it's not that we don't believe in freedom of speech," Peter had said, according to his father. "You can say whatever you want. We'll just throw you in an oven."
"Peter," his father pleaded in the letter, "you will have to shovel our bodies into the oven, too. Please son, renounce the hate, accept and love all."
He hasn't heard from Peter since.
