Opinion | How to Win a Presidential Debate

If you’re a typical American voter in any party, allow me to let you in on a little secret: What matters most to you in a presidential debate probably isn’t the same thing that gets the most attention from the candidates, the campaigns and their allies in the immediate aftermath of those big televised showdowns.

I’ve learned this from studying American reactions to almost every general election presidential debate since 1992. I’ve sat with small groups of voters selected from pools of thousands of undecided voters nationally, watching more than two dozen presidential and vice-presidential debates in real time, and it still amazes me that minuscule moments, verbal miscues and misremembering little details can matter so much in the spin room and to partisan pundits afterward. Yet those things often have little to no discernible impact on the opinions of many people watching at home.

To be fair, some of the debates I watched with voters, like Bill Clinton and Bob Dole’s in 1996, had no major impact on the electorate’s mood. Others — like the three-way town hall debate with Mr. Clinton, George H.W. Bush and Ross Perot in 1992 and the first George W. Bush-Al Gore debate in 2000 and the three Donald Trump-Hillary Clinton collisions — arguably changed history.

As the first scheduled debate between President Biden and Mr. Trump unfolds this Thursday, the key moments that will have the greatest impact on the remaining undecided voters are those in which the candidates attack each other in defining ways or undermine the political case that each wants to present to Americans. Viewers will quickly decide whether the accusations are fair and the responses effective. From Ronald Reagan’s “Are you better off than you were four years ago?” in 1980 to Barack Obama emphasizing hope and change in 2008 to Mr. Trump telling Mrs. Clinton in 2016 that she would “be in jail” if he won, I think those key debate moments made a meaningful difference in shaping the opinions of undecided or wavering voters who related to what they heard; I certainly saw it in my focus groups and public opinion research. These moments mattered more than any candidate flub or gaffe.

And sometimes it’s a feeling rather than a specific moment that matters. The best examples are John Kerry in the 2004 debates and John McCain in the 2008 debates: Both men were good public servants with impressive personal narratives, and neither said anything wrong in their debates. But neither did they say anything especially or memorably right. Many voters were left feeling unmoved and therefore unaffected.

At the risk of offending every high school debate coach in America, many voters respond to style more than substance. The well-delivered quip lingers longer than the litany of facts, and the visual often trumps the verbal. It’s not just that the electorate tends to be drawn more to younger and more attractive candidates (like Mr. Obama, Mr. Clinton and John F. Kennedy) or to those with more commanding stage presence (which Mr. Reagan had over Jimmy Carter and Walter Mondale, and George H.W. Bush had over Michael Dukakis). While the 2016 and 2020 debates featuring Mr. Trump certainly upended our collective expectations about what exactly is presidential, listening to the voters describe each debate and their gut impressions of the candidates is more instructive about the eventual election winner than getting swept up in spin and punditry.