Convention Bounce

Support for presidential candidates usually spikes during their nominating conventions—a phenomenon so reliable its measurement has become a staple of preelection polling and commentary. Some of these convention bounces have been very short-lived, the race quickly reverting to its pre-convention level between the candidates. Others have been more profound—a coalescing of voter preferences that has charted the course for the remaining campaign.

While convention bounces have been apparent since 1968 (previous election polling was too infrequent for reliable identification of such bounces), focus on the convention bounce owes much to Bill Clinton, who soared from a dead heat against Republican presidential incumbent George H. W. Bush before the 1992 Democratic convention to nearly a 30-point lead after it. While the race later tightened, Clinton never again ...