Small changes in voter preferences after the debate do not mean the course of the presidential race has shifted, says the Northeast expert.
![President Joe Biden speaks during the presidential debate.](https://news.northeastern.edu/wp-content/uploads/2024/07/Joe_Biden_1400.jpg?w=1024)
President Joe Biden's performance during the first presidential debate has been widely viewed, with critics even within his own party calling him aside. But the question remained: Would Biden's shaky performance against former President Donald Trump result in a noticeable drop in the polls for the president?
According to a new exhibition from the Northeastern University Data Project CHIP50the answer is no.
Led by David Lazer, distinguished university professor of political science and computer science at Northeastern, the report says the debate had little to no impact on citizens' voting preferences. Lazer hopes the report will help illustrate the dangers of making a mountain out of a hill when it comes to media interpretation of data.
“Even the New York Times, which is usually better for this, talked about a very small change that was completely statistically insignificant as if it were proof that it was a shift toward Trump after the debate,” says Lazer. “I hope journalists see this and say, 'Maybe we need to be careful about over-interpreting the noise as a real signal.'
![Headshot by David Lazer.](https://news.northeastern.edu/wp-content/uploads/2024/02/022124_MM_David_Lazer_018.jpg?w=1100)
![Headshot by David Lazer.](https://news.northeastern.edu/wp-content/uploads/2024/02/022124_MM_David_Lazer_018.jpg?w=1100)
Seeing the dominant narrative coming out of the debate, Lazer and the team at CHIP50 decided to test the hypothesis that Biden had lost ground in public opinion after the debate. Specifically, Lazer says, they didn't survey two different cross-sectional groups of people before and after the debate, like most polls. Instead, the team was able to survey the same group of respondents from a survey conducted prior to the debate.
Lazer says using the same group of people helps make the results more accurate, which is important in a poll that inherently has a margin of error.
What the report finds is that Biden kept 94% of the people who said they would support him before the debate. For Trump, 86% of people who said they would support him before the debate said they would after the debate.
“What we're seeing is that there's some flipping — maybe 10 percent or so of people changing what they answer — but that the net result is not a shift away from Biden,” Lazer says. “If anything, Biden seems to hold his people somewhat better than Trump.”
In fact, overall, the shift in support was actually more in favor of Biden, though Lazer notes that it's not statistically significant and within the margin of error.
There was very little change among the candidates: 1% of people who said they would vote for Biden before the debate switched to Trump, while 3% switched from Trump to Biden. Likewise, respondents who said they weren't sure who they would vote for before the debate were slightly more likely to shift to favoring Biden after the debate.
“[It all] points in the same direction, which is that it seems unlikely, based on our data, that things went Trump's way after the debate,” says Lazer. “If anything, our assessment is a little bit more toward Biden, but I wouldn't make too much noise about it.”
There were more significant, but still small, shifts toward people preferring other third-party candidates after the debate. About 4% of Biden supporters and 6% of Trump supporters said they would prefer the “Other” category in the post-debate survey. Meanwhile, 6% of those who preferred another candidate before the debate shifted to both Biden and Trump after the debate, resulting in a small net effect.
The relatively flat trend of poll numbers in the 2024 election is indicative to Lazer of how polarized politics has become where very little will sway voters from their preferred party.
“Trump was convicted of a series of felonies,” says Lazer. “The impact it had on the investigations was zero. Biden had a debate where most people said he proved he was too old. Respondents said, “Yes, I saw that. He is very old. I still vote for him.' The numbers just don't move.”
Lazer says that “our overconfidence in seemingly accurate statistics” is nothing new during an election cycle, but warns that the 2024 election is different.
“In this case it actually affects decision-making,” says Lazer. “If you do the narrative that things are cratering for Biden, it might affect whether Biden stays in the race. I don't know if he should stay in the race or not, but decisions have to be made with accurate information.”