Happy Thanksgiving! Please enjoy a re-air episode from April 2018 with Lilliana Mason. Yes, identity politics is breaking our country. But it’s not identity politics as we’re used to thinking about it. In Uncivil Agreement: How Politics Became Our Identity, Lilliana Mason traces the construction of our partisan “mega-identities”: identities that fuse party affiliation to ideology, race, religion, gender, sexuality, geography, and more. These mega-identities didn’t exist 50 or even 30 years ago, but now that they’re here, they change the way we see each other, the way we engage in politics, and the way politics absorbs other — previously non-political —spheres of our culture. In making her case, Mason offers one of the best primers I’ve read on how little it takes to activate a sense of group identity in human beings, and how far-reaching the cognitive and social implications are once that group identity takes hold. I don’t want to spoil our discussion here, but suffice to say that her recounting of the “minimal group paradigm” experiments is not to be missed. This is the kind of research that will change not just how you think about the world, but how you think about yourself. Mason’s book is, I think, one of the most important published this year, and this conversation gave me a lens on our political discord that I haven’t stopped thinking about since. If you want to understand the kind of identity politics that’s driving America in 2018, you should listen in. Books recommendations: Ideology in America by Christopher Ellis and James Stimson  Homegoing by Yaa Gyasi  The Power by Naomi Alderman My book is available for pre-order! You can find it at www.EzraKlein.com. Want to contact the show? Reach out at ezrakleinshow@vox.com You can subscribe to Ezra's new podcast Impeachment, explained on Apple Podcasts, Spotify, Stitcher, Overcast, Pocket Casts, or your favorite podcast app. Learn more about your ad choices. Visit podcastchoices.com/adchoices