After the 1948 presidential election polls predicted a Dewey victory of between five to 15 percentage points, polling pioneers worked hard to rebuild their reputations.
Preelection polls gradually became far more reliable. However, they underestimated Ronald Reagan’s margin of victory against Jimmy Carter.
Right before the campaign’s only presidential debate on October 28, 1980, polls showed Carter ahead by as much as eight points.
With a majority of the electorate believing government had become too powerful, Reagan won in a landslide, taking the highest number of electoral votes ever won by a non-incumbent presidential candidate.