It’s been said that politics is perception, and nowhere is that more true than during a presidential debate. In 1960, millions of Americans tuned into the now legendary debate between John F. Kennedy and Richard Nixon. Many who listened to the exchange on the radio may have felt Nixon prevailed. But the cameras told a different story. Television viewers were drawn towards JFK’s more polished, confident appearance. That moment ultimately tipped the scales toward his victory that November.
History will also remember the June 27 debate between incumbent Joe Biden and former president Donald Trump. Viewers saw a halting, often confused Biden struggling to maintain focus under Trump’s barrage of personal attacks. Since then, however, a dramatic series of events has turned the 2024 election season in a new direction.
But how much do presidential debates really matter in terms of swaying potential voters?
Dustin Carnahan is an associate professor in the Department of Communication. He studies how people interact with political messaging to form their beliefs and decisions. Carnahan says research shows debates generally have little impact on voter choice.
“Debate viewers tend to be among the most politically engaged and thereby likely to have their minds made up well before the debate,” said Carnahan. “That said, some research has suggested that candidates’ debate performances can impact how favorably they are perceived by voters, which can affect the choices of undecided voters. Additionally, a lopsided debate performance or significant gaffe committed by a candidate can have a lasting effect on candidate evaluations.”
Going into the debate, tensions were high among the two candidates. For months, Trump repeatedly mocked Biden’s age, insinuating he was unfit for the office. That sentiment was also reflected in the media, with many pundits questioning the president's energy. The Biden campaign wanted to refute those claims and hoped a strong showing by their candidate would convince potential voters of his competence.
However, just minutes into the debate, things began to unravel for Team Biden.
“With this backdrop, President Biden did what he couldn’t afford to do,” Carnahan said. “He had an exceptionally poor performance, and it proved catastrophic to his campaign. This wasn’t a matter of a few gaffes or a less-than-inspired showing; from start to finish. Biden struggled mightily – speaking with a hoarse voice, trailing off in his responses, and, in one noteworthy moment, seemingly losing his train of thought on a question about Medicaid.”
But despite this, Carnahan says most major polling firms showed only slight movement in favor of Donald Trump after the debate. He notes that Reuters/Ipsos had Trump ahead by two percentage points in mid-June – the same margin they found in mid-July. Other polls from Rasmussen and Harris were virtually unchanged.
Then, on July 21, everything changed.
On that Sunday afternoon, President Biden announced his withdrawal from the presidential race, clearing the way for Vice President Kamala Harris to become the presumptive Democratic nominee. The effects are still reverberating, but the shockwave has injected new life into the Democratic Party and has forced the Trump campaign to overhaul its entire strategy.
Carnahan thinks the historical significance of the first 2024 presidential debate will not be its effect on the mindset of the electorate but how it served as a tipping point among many party leaders already concerned about Biden’s capacity to lead a successful campaign against Trump.
“The debate shook the confidence of leaders within the Democratic Party about whether the Biden campaign would be able to make up the ground it needed to retain the presidency, leading Biden to take the unprecedented step to move aside,” he said.
The outcome of the 2024 presidential election remains to be seen. But it’s clear that the showdown the nation witnessed in June will look nothing like the race to the ballot box this November.