How important are presidential debates?

Presidential debates are among the most-watched political events, providing voters with direct comparison of candidates. However, research suggests their impact on election outcomes is typically modest—they rarely produce large, lasting shifts in voter preferences, though they can reinforce existing views and occasionally change close races.

The history of televised debates

The first televised presidential debates were the famous 1960 Kennedy-Nixon encounters. The myth that radio listeners thought Nixon won while TV viewers favoured Kennedy (due to Nixon's appearance) is often overstated, but the debates established television's importance in campaigns.

After a 16-year gap, debates resumed in 1976 and have occurred every election since. The Commission on Presidential Debates (CPD) organised general election debates from 1988 until 2024, when major candidates began negotiating directly with networks.

Do debates change elections?

Political science research generally finds that debates produce modest effects. Most viewers are already committed to a candidate and interpret debate performance through partisan lenses. Post-debate "bounces" in polls often fade within days.

However, debates may matter more when:

• The race is very close
• A candidate is relatively unknown
• A major gaffe or memorable moment dominates subsequent coverage
• The debate reveals new information or concerns

Correlation between debate performance and polling change is not necessarily causal—other campaign events occur simultaneously.

Notable debate moments

1980: Reagan's "There you go again" and "Are you better off?" lines helped crystallise doubts about Carter. 2012: Obama's passive first debate performance allowed Romney to close the gap before Obama recovered. 2024: Biden's debate performance contributed to subsequent Democratic nomination developments, illustrating how debates can affect not just the general election but party confidence in candidates.