Debates have become a defining part of U.S. civic life. They trace a clear path from 19th-century face-offs like Lincoln and Douglas to the broadcast era that changed how people decide who to support. The 1960 Kennedy–Nixon televised event drew over 66 million viewers and set a modern tradition. Radio moments such as the 1948 Dewey–Stassen exchange also shifted public attention. Today’s format blends TV, online media, and social platforms into a multi-channel stage. Top debates since 1976 show massive reach: 84 million for Clinton/Trump (2016), 80 million for Carter/Reagan (1980), and 73.1 million for Trump/Biden (2020). These numbers prove debates are not niche — they are a central part of election seasons and a key moment in any campaign. In this Ultimate Guide, we map eras, compare rules across systems, and explain how design choices shape what voters learn about candidates and issues. Expect practical insights on formats, moderators, and the future of these public f...