Susan Benkelman is director of accountability journalism at the American Press Institute.

On the night before Donald Trump was inaugurated as president, the right-wing extremists who were celebrating the occasion at their “DeploraBall” had a big concern: that someone would break into a Nazi salute. Antifa was protesting outside, after all, so the risk of provocation was high — and so was the relief when it didn’t happen.

The “deplorables” might all have fit into one basket by Hillary Clinton’s reckoning, but even as they appropriated her label as a badge of honor, the ball’s organizers took great pains to differentiate themselves from the white-nationalist elements of the alt-right. They wanted to be at their movement’s outer edge without stepping over it, especially while the mainstream media was paying attention.

This was a careful calibration for a group that often seemed splintered, disorganized and interested mostly in calling attention to themselves. In fact, they knew exactly what they were doing: They were attempting to establish a new set of parameters for political conversation, widening the “Overton window” of what is acceptable in public discourse.

Their effort began long before the DeploraBall, Andrew Marantz writes in “Antisocial: Online Extremists, Techno-Utopians, and the Hijacking of the American Conversation.” By the time Trump won the 2016 election — a victory these right-wingers took credit for — they had become highly skilled in using social media to podcast, live-stream and meme their messages of misogyny, racism and other toxins into the feeds of the unsuspecting.

Social media was the perfect milieu. It gave them cover when they wanted to remain anonymous; a means of amplification when they wanted to foment chaos and conflict; and a ready-made vehicle for their inside jokes, dog whistles and frog-faced memes that carried bile with a wink and a nod.

Social media also gave them an unfettered platform, Marantz argues, one set up by Silicon Valley entrepreneurs who have overtaken the mainstream media as the “new gatekeepers” of information. What they really did is leave the gates wide open.

The deplorables crashed them anyway, just for the shock value. They were able “to hijack the American conversation,” Marantz writes, by grabbing attention through trauma and insult. Conflict equals attention, the author says more than once, and social media’s algorithms reward engagement but are blind to quality.

Marantz’s book comprises some of the articles he has done as a staff writer for the New Yorker, where he covers the intersection of extreme politics and online culture, what he calls “the-bad-guys-on-the-internet beat.”

The repurposing of his New Yorker work at times gives the book a kludgy feel. But the book goes beyond the individual magazine pieces by providing valuable connective tissue that Marantz uses to weave these stories together with history and context. The effect is to inspire a larger contemplation of what the collapse of civil discourse means about our society.

Marantz is above all a storyteller, so his narratives are crucial. He has a keen eye for detail and a deft ability to let readers discover and then ponder the movement’s ironies — and there are many — without hitting them over the head. (The DeploraBall, for example, was held at the National Press Club, the epitome of the old media establishment.)

The author’s liberal use of asterisks to indicate asides at the bottom of pages can seem distracting at first. But they ultimately form a kind of meta-metaphor: a book about the Internet lets the reader decide whether to navigate away from the text, as in a hyperlink, to get to an ancillary point or return to it later.

His first-person accounts of embedding with people whose views he finds morally repugnant are at once amusing and disturbing, but mostly the latter. They would often say something vile, only to assert that they were just kidding. But were they? They would also treat their handiwork with dismissiveness, calling it “just a thing on the internet.”

Marantz chronicles the outrageous behavior but then, mercifully, elevates the conversation. In key moments, he pushpins into his text a phrase inspired by Richard Rorty, a pragmatist philosopher who argued that a society’s vocabulary shapes its beliefs: “To change how we talk is to change who we are.”

There is little doubt the Internet has changed how we talk. But it has done more than that; it’s activated and augmented a dark fringe of society that had once been cordoned off by the old gatekeepers. Perhaps this fringe is larger than we knew — but it probably is not as large as social media has made it seem. Disinformation experts, in fact, say one of the main objectives of nefarious online actors is to make their movements appear more popular than they really are. Welcoming old-guard media reporters like Marantz into their dens is part of that strategy, and he acknowledges the challenges of writing about these movements without amplifying them.

As for the new gatekeepers, the platforms today are furiously trying to reel back the conversation, with a series of judgment calls they clinically term “content moderation,” a process Marantz chronicles at Reddit.

No one knows where this culling will leave the purveyors of hate. A year after their inauguration ball, the deplorables held another party that Marantz described as “sad and stilted.” Perhaps they were still trying to parse their identities, especially after an avowed neo-Nazi rammed his car into counterprotesters at a white-supremacist rally in Charlottesville the previous August, killing one and injuring 35 others.

After Marantz takes us on his journey into their psyches, it’s hard to believe they are done. With Trump in the White House, perhaps they feel like they’ve succeeded in widening the Overton window.

On the very far right, there are troubling signs that the hijacking is being taken to new, surreal levels, like white nationalists’ use of the language of environmentalism to push an “ecofascist” agenda, as identified by University of Michigan professor Alexandra Minna Stern, another chronicler of the alt-right. Stories like that make it seem that the window isn’t just shifting; it’s offering a view into the abyss.

But there are also indications that the window is shifting leftward as well, with phrases like “Green New Deal” and “Medicare-for-all” entering the lexicon, and the current debate over whether news organizations are too careful with the terms “racist” and “racism.”

Our words, after all, do matter, and Marantz makes a compelling argument that they matter more than we think. They may not merely reflect who we are. They may actually determine it.

Antisocial

Online Extremists, Techno-Utopians, and the Hijacking of the American Conversation

By Andrew Marantz

Viking.
380 pp. $28