In this 6 1/2 minute video, CGP Gray explains how the mathematics of a one person/one vote system inevitably leads to a two-party system that pleases almost no one.

Also from CGP Gray:

Lisa Wade, PhD is a professor at Occidental College. She is the author of American Hookup, a book about college sexual culture, and a textbook about gender. You can follow her on Twitter, Facebook, and Instagram.