From Primary to General Election: A Forecast of the Presidential Vote

Yogi Berra might have said it: the best predictor of an election is, well, an election. Not a trial-heat conducted by opinion polls, but a real election of voters going to the polls. In the U.S., at least, what is known as a “general” election is preceded by a “primary” election, and that has been the case for presidential contests since 1912. So is the voting in presidential primaries a leading indicator of the vote in November? Remarkably so, as it turns out. How well presidential candidates do in primary elections foretells their prospects in the November election with great accuracy. What is more, the use of primaries as a vote predictor makes it possible to include in the forecast model both the candidate of the incumbent party and the candidate of the party out of the White House. The forecast for 2004 uses candidate vote shares in primaries, not just a win-lose dichotomy as done in the model used to predict the vote in 2000 (Norpoth 2001).