"Game changer." We heard it so many times during the 2012 U.S. presidential election. But what actually made a difference in the contest―and what was just hype? In this groundbreaking book, John Sides and Lynn Vavreck tell the dramatic story of the election―with a big difference. Using an unusual "moneyball" approach and drawing on extensive quantitative data, they look beyond the anecdote, folklore, and conventional wisdom that often pass for election analysis to separate what was truly important from what was irrelevant. The Gamble combines this data with the best social science research and colorful on-the-ground reporting, providing the most accurate and precise account of the election yet written―and the only book of its kind.