The Iowa Caucuses Are Known for Surprises—Here Are 3 of the Biggest Upsets

Victory in Iowa doesn’t guarantee a nomination at the party convention, but it can turn unknowns into stars. Simultaneously, it can signal the end of once-promising campaigns. Iowa, a Midwestern state of about 3 million people and most famous for its agriculture, becomes the center of the U.S. political universe every four years because of its unique position as the first state to cast a vote on presidential hopefuls. Adding to the drama is the caucus format, which are organized by the state’s political parties and typically held in January. The caucus bedevils prognosticators because it tends to break late....