On Tuesday night, former President Donald Trump and Vice President Kamala Harris met for their first, and potentially only, presidential debate, with each candidate hoping to gain a crucial advantage over the other in a very close race. And based on early reviews from the American public, it seems like Harris came out on top.
As of 1 p.m. Eastern, 538 has collected three national polls and one swing-state poll that were conducted since the debate.* In all of them, more people who watched the debate said Harris won the debate than said Trump did. On average, 57 percent of debate watchers nationally said Harris turned in the better performance; only 34 percent said Trump did.
CNN/SSRS also conducted a poll of the same respondents before the debate, allowing us to compare what they thought about the candidates before the event with what they thought about the candidates after it. And according to their poll, Harris’s net favorability rating among debate watchers rose from -11 percentage points (39 percent favorable, 50 percent unfavorable) before the debate to +1 point (45 percent favorable, 44 percent unfavorable) after it. Trump’s net favorability rating, however, barely changed (from -11 points to -12 points).
That’s all obviously good news for Harris – but there are a few caveats here. First of all, it’s still quite early. Only a few polls have been conducted since the debate, and we’ll have more data very soon that will either confirm their findings or throw them into doubt. It’s also possible that perceptions of the debate will evolve as viewers digest it (and as clips get shared with those who didn’t watch). A poll conducted, say, this weekend may find a different winner than a poll conducted the night of.
The second caveat is that, even if Harris did turn in the better performance, that doesn’t necessarily mean that the debate will give her a significant boost in the polls. In the CNN/SSRS poll, only 4 percent of debate watchers said the event changed their mind about whom they were voting for. An additional 14 percent said it made them reconsider but not change their mind, while a whopping 82 percent said it did not affect their choice.
CNN/SSRS did not ask respondents directly whom they were supporting, but two other post-debate polls did (both conducted or sponsored by Republican firms). SoCal Strategies/On Point Politics/Red Eagle Politics found Harris leading Trump nationally by 3 points after the debate, virtually indistinguishable from the 2-point lead they gave Harris in mid-August. And in their survey of debate watchers in the big seven swing states, Trafalgar Group/InsiderAdvantage found the two candidates virtually tied after the debate at about 48 percent apiece. The same sample said that, before the debate, they were planning to vote for Trump by around 1 point.
Democratic presidential nominee Vice President Kamala Harris speaks at the National Constitution Center, Tuesday, Sept.10, 2024, in Philadelphia.
AP Photo/Alex Brandon
Again, this is only two surveys, so it’s far too early to make any pronouncements that the debate didn’t significantly move the needle. We recommend keeping an eye on 538’s polling averages over the next several days to see if future polls produce any movement.
The third caveat is that, even if Harris does rise in the polls after the debate, those gains could be fleeting. CNN polling also found that Americans thought former Secretary of State Hillary Clinton turned in the best performance in all three of her debates with Trump in 2016, and she rose in national polls after the first two of them (although other factors, such as the “Access Hollywood” tape, likely factored into that as well). But, of course, the race tightened in the final days and Clinton went on to lose that election.
Going further back, CNN polling found that Americans overwhelmingly considered former Massachusetts Gov. Mitt Romney the winner of the first debate in 2012, after which he improved in the polls as well. But Americans preferred former President Barack Obama’s performance in the two subsequent debates, and he eventually won.
In 2008 and 2020, the same candidates (Obama and now-President Joe Biden, respectively) were perceived to have won every debate and also went on to win the elections. But those years, there were also multiple debates (as of now, Harris and Trump are not scheduled to meet again, although there will be a vice-presidential debate on Oct. 1), and they happened much closer to Election Day than this year’s debate. (If not for the June debate that led to Biden’s withdrawal from the race, this week’s debate would have been the earliest general-election presidential debate in modern history.) In other words, this year, there is even more time than usual for the debate to fade in voters’ minds.
The best way to think about it? As anticlimactic as this may sound, the presidential election was very close before the debate, and it will likely continue to be very close after it.
Footnotes
*Not counting a J.L. Partners/DailyMail.com poll that was conducted solely among independent voters. For the record, though, these respondents also felt that Harris performed better in the debate, 49 percent to 43 percent.