It’s too early to judge the outcome of the presidential debate, but polls already suggest that Kamala Harris could be on the verge of winning.
Early surveys of people watching the debate found that most viewers thought she won, and the candidate seen as the winner in post-debate polls generally tends to win in the polls.
Early polls since Tuesday’s debate show the Democratic candidate doing better than polls conducted before. If history is any guide, it will be a few more days, if not a week, before the full extent of the post-debate surge becomes clear.
This time, there is another unpredictable element looming: what authorities have described as a second attempt to assassinate Donald J. Trump. It is not yet clear how voters might react, but if it refocuses the conversation away from the debate, it could put a damper on Ms. Harris’s rise.
Race Status
Overall, Vice President Harris leads Mr. Trump by three percentage points nationally, according to the New York Times polling average. That’s already one point better for Ms. Harris than our average on Wednesday.
The contest is even tighter in the key states, where no candidate has a lead of even a single percentage point in enough states to win the 270 electoral votes needed to win the presidency.
The current leader in the polling average in five of the seven key states – Michigan, Pennsylvania, Georgia, North Carolina and Arizona – is only one point ahead or less.
There were very few post-debate polls in any of the seven states. In fact, much of the change in our state averages is attributable to the polls conducted Before the debate, but published afterwards.
What changed: before the debate
What has changed can be divided into two groups: polls conducted before the debate and polls conducted since.
First, the pre-debate polls released last week: They may seem outdated, but it’s not that simple. In many states, there haven’t been many recent polls, because the Labor Day holiday put a pause on many polls.
A series of high-quality opinion polls showed Ms. Harris doing well, at least in relative terms, in Wisconsin, Iowa, Virginia, North Carolina and even Alaska. Mr. Trump, by contrast, did well in Georgia and Michigan.
These results didn’t change our state polling averages much, but they were nonetheless good news for Ms. Harris — and perhaps a bit of a surprise. After all, the polls we saw before the debate showed a tight, tight race, with several high-quality outlets — Times/Siena, YouGov/Economist, Marist, Pew Research, and KFF — calling the race down to a single point. One might have expected a tight race nationally to give Trump a clear lead in key states.
But that’s not what happened. Instead, Ms. Harris took a slight lead in our average in North Carolina, after the Quinnipiac and SurveyUSA polls had her ahead by three points, while Mr. Trump now has the edge in Georgia. And Ms. Harris solidified her modest lead in Wisconsin, where the venerable Marquette Law School poll has her ahead by four points.
What changed: after the debate
The few post-debate polls show signs of a rebound for Harris.
By our average, she has already gained about a point nationally, going from a 1.7-point lead Wednesday morning to a 2.7-point lead Monday morning. That one-point change has been relatively consistent across the six national polls that conducted surveys before and after the debate.
In the coming days, Ms. Harris could gain even more ground. For one thing, most of the post-debate polls come from online panels. They tend to vary less than other surveys because they are often composed of highly engaged voters and carry more weight than the typically more volatile telephone polls that are likely to arrive this week.
There’s another reason: Many people don’t watch the debates, but they do listen to the coverage that follows, such as the incessant discussion of Mr. Trump’s false claim that Haitian immigrants in Springfield, Ohio, ate pets. Extended coverage of a debate can help the presumptive winner as much as the debate itself, generating additional poll gains in the days or even weeks that follow.
Will the rise in polls last?
The period following a debate is a difficult time for pollsters.
On the one hand, debates can change the course of a race in lasting ways—just ask President Biden. Even leaving aside this recent example, polls regularly shift after the first debate and never return to their previous levels. That’s what happened in 2000, 2004, 2008, and 2012.
On the other hand, debates can create shifts in the political environment that don’t last. Just ask Hillary Clinton, who took a commanding lead after the 2016 debates only to see it fade in the final week. Something similar happened to Mr. Biden in 2020.
These post-debate shifts in opinion were fleeting, but they could have reflected real shifts in expressed preferences, that is, driven by people giving different answers to a pollster before the debate. One can imagine, for example, some Nikki Haley voters who shifted to Mr. Trump but who might now say they are undecided after watching the debate. Even if these voters do shift to Mr. Trump, we will see him fall in the polls after the debate.
It is also possible that these post-debate fluctuations are partly a mirage: they could simply be due to changes in poll responses, not changes in voter preferences.
Regardless, it’s a great reminder of the limits of polling. If the election were held on Tuesday, would Ms. Harris’s rebound actually materialize? Would Haley’s swing voters ultimately vote for Mr. Trump, stay home, or vote for Ms. Harris? Did Ms. Harris gain new support from voters who hadn’t heard enough about her but saw in the debate someone capable of running the presidency? We simply can’t tell.
All these questions will be asked on election morning. We will not know whether undecided voters will flock to one party, whether the polls were skewed by different response rates, or whether, perhaps, the polls are accurate.
What we do know is that the polls are so close that even a common polling error could give either side a decisive victory. Just look at what would happen if the polls were exactly wrong as they were two or four years ago.
If the polls were wrong as they were in 2020, Mr. Trump would win the election battle. Conversely, Ms. Harris would win by a landslide if the polls were wrong as they were in 2022.
It’s easy to imagine either scenario. It’s hard not to see a result like “Harris +4 in Wisconsin” without feeling a sense of foreboding, since Wisconsin has been a hotbed of polling errors in the last two presidential elections. On the other hand, Republican-leaning corporate polls have been surging in recent weeks, just as they did before the 2022 election, when the promised “red wave” failed to materialize.
It’s also possible that these two phenomena will largely cancel each other out, and the polls will have their best year in a decade. After all, today’s polls show a near-repeat of the 2020 election, with nearly every state poll within a point or two of where they were four years ago.
If there is one thing that is easy to imagine in today’s polarized country, it is a repeat of the last election.
