The word “meme” might bring to mind a viral picture of a weird-looking cat with silly text, a tweet or video showing up everywhere online. But some political memes can be downright dangerous, according to a new book — “Meme Wars: The Untold Story of the Online Battles Upending Democracy in America.” Its authors argue that memes have inspired cultural battles over the last decade both on- and offline. Marketplace’s Kimberly Adams spoke with Emily Dreyfuss, a senior editor at Harvard Kennedy School’s Shorenstein Center and one of the book’s co-authors, about how far-right or extremist groups use memes as weaponized tools in their attempts to influence American politics.