Many people who watched the attack on the Capitol unfold on Jan. 6, 2021, were astonished by what they saw. The mobilization of Trump supporters who tried to prevent Congress from authorizing Joe Biden’s election, the violent invasion of the building, the face-painted rioter wearing a horned and bear-skinned headdress — it all seemed surreal, almost unbelievable.

Yet little of it surprised the authors of “Meme Wars: The Untold Story of the Online Battles Upending Democracy in America.” The authors, who are all researchers at Harvard’s Shorenstein Center on Media, Politics and Public Policy, say the disturbing events of Jan. 6 were “entirely foreseeable” to anyone who had watched the “Stop the Steal” meme go viral on social media.

“Meme Wars” was written by Joan Donovan, a sociologist who researches technology and social movements; Brian Friedberg, an ethnographer who studies Internet subcultures and alternative media; and Emily Dreyfuss, a technology journalist who has contributed to Globe Ideas. They present a disturbing account of how digital memes move hearts and minds and mobilize the masses, often spreading dangerous ideologies and disinformation. And they make a compelling case that you can’t understand American politics without grasping how memes get weaponized.

My interview with Dreyfuss has been condensed and edited.

Memes are concise ideas that spread through culture. We commonly think of memes as images on the Internet accompanied by some brief text. The interplay between the words and pictures presents an idea. But memes predate the Internet. As originally defined by Richard Dawkins, memes go all the way back to the beginning of human culture. They can be slogans, images, flags, symbols, or gestures. What makes a meme a meme is that, like a pill capsule, it’s a compact delivery mechanism for something complex.

What are some examples of effective memes?

Our book is concerned with political memes. “Let’s Go, Brandon” and its counterpart “Dark Brandon” are two good recent examples. These memes display the classic characteristics of a successful meme. They are authorless. No one thinks about who came up with them. They designate an in-group and an out-group. People who use the “Let’s Go, Brandon” meme are united in their disdain for the current president. People who use “Dark Brandon” are united in their fervent support of the president. The memes resonate with preconceived ideas people hold. They are also flexible and can be remixed endlessly in all sorts of formats and mediums — from hats and image macro memes made in Photoshop to songs and chants at ballgames. Memes are also weird in a way that makes them a funny inside joke for those in the know and a curious thing to research for those who are not.

In this last regard, both memes are potential openings to a rabbit hole of political ideology. If you don’t know what “Let’s Go, Brandon” means, you Google it. What you find in those search results and where you find it can determine what path your quest for knowledge takes.

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Does this mean seeing a meme can be a slippery slope to becoming radicalized?

No, it’s not that simple. But memes can be “red pills,” provocative ideas that instantly change your understanding of the world. Once you know it, you can’t unknow it. Before “The Matrix” made “red pill” a popular metaphor, they were called “hate facts.” A hate fact is an intentionally radical and offensive claim that may or may not be true and is intended to upset you and make you hate a specific group.

How have memes furthered Donald Trump’s agenda?

Memes have been essential to Trump’s rise and a key part of his messaging strategy. Trump was uniquely situated to be memed because he was so famous and there existed so many images and videos of him for meme makers to play with. He was also already a living caricature of a certain kind of powerful white rich man. And he was embraced and beloved in memetic communities before he ever ran seriously for president. As with any good meme, Trump was just weird enough in how he looked and what he said that he made for immediately sticky memes.

After Trump won the presidency, memes played a huge role in how he communicated with his base, and they still do. He retweeted memes. He [was the source of] some, like “covfefe.” And he strategically deployed others, like “stop the steal,” which he presented to his base long before the 2020 election to lay the groundwork for his loss. Or “Biden crime family,” which he and his biggest supporters shared across the social web at the end of the 2020 election.

Why do so many people think of memes as jokes rather than a powerful form of political communication?

Because most Internet memes are jokes. Some are apolitical cat memes. But many political or ideological memes are also jokes of one kind or another. Most commonly, they’re in-jokes that mock a perceived other and signal to their in-group that they have a common belief. And even when they’re not funny, memes are weird. Consider the slogan “Stop the Steal.” Its ungrammatical format makes it odd and memorable. That kind of oddity allows those in the out-group to dismiss it. They think, “How could #stopthesteal matter when it doesn’t even make any sense?”

The far right seems to be winning the meme wars at the moment. But you and your coauthors write that these techniques actually were pioneered by Occupy Wall Street protesters in 2011.

Coming on the heels of the Arab Spring (aka the Twitter revolution), Occupy Wall Street operationalized the use of social media and social media spectacle to foment support for the movement. It showed that social media could be used to drive media interest, which would, in turn, drive real-world participation. Occupy Wall Street used the Internet to spread from New York very quickly across the country and the whole world. The right, particularly Andrew Breitbart, Stephen Bannon, and Alex Jones, watched this and saw that the tech strategy of Occupy Wall Street was a model they could follow.

Can today’s political left do a better job using memes? If so, should it?

It absolutely could and recently has been trying to level up with its use of “Dark Brandon” to co-opt and counter the “Let’s Go, Brandon” meme from the right. The White House has even turned to memes to shame Republican politicians for their hypocrisy on loan forgiveness.

I don’t know that the left should do a better job at meme warfare. One major takeaway from the book is that winning a meme war doesn’t often lead to policy changes or good personal outcomes for the people involved. The meme wins and the people lose. Having said that, the left is not always good at articulating its core beliefs and values succinctly or at all. And it would benefit from doing a better job of that.

But for the left to actually engage in meme warfare the way the far right does would require a sea change in the culture of the Democratic party. The party and the way it interacts with its supporters is so fundamentally different that any attempt on the left to actively counter the far right meme machine would be a top-down effort, which is rarely successful. Usually, memes have to grow organically out of their communities.

Evan Selinger is a professor of philosophy at the Rochester Institute of Technology, an affiliate scholar at Northeastern University’s Center for Law, Innovation, and Creativity, and a scholar in residence at the Surveillance Technology Oversight Project (S.T.O.P.). Follow him on Twitter @evanselinger.

Work at Boston Globe Media