Just who are the Koch brothers -- and when, and why, did they decide to spend billions of dollars in order to change the direction of American politics? On this installment of our show, a conversation with the well-respected political reporter Jane Mayer, who is a staff writer for The New Yorker as well as the author of an acclaimed new book, "Dark Money: The Hidden History of the Billionaires Behind the Rise of the Radical Right." It's a book that is, per The Washington Post, "deeply researched and studded with detail.... [It] could inspire a more intense discussion about the impact of this wealthy conservative cadre on the Republican Party and the recent course of American politics." And further, from The New York Times Book Review: "The book is written in straightforward and largely unemotional prose, but it reads as if conceived in quiet anger. Mayer believes that the Koch brothers and a small number of allied plutocrats have essentially hijacked American democracy, using their money not just to compete with their political adversaries, but to drown them out.... 'Dark Money' emerges as an impressively reported and well-documented work.... The importance of 'Dark Money' [flows] from its scope and perspective.... It is not easy to uncover the inner workings of an essentially secretive political establishment. Mayer has come as close to doing it as anyone is likely to come anytime soon.... She makes a formidable argument."