Methodology: Harris-Trump Swing Voters
To identify swing voters, we used the same methodology from our inaugural report, but updated to replace Biden with Harris:
In our surveys, we asked respondents various questions to create our scoring method. These include:
Whom a respondent voted for in the 2020 presidential election;
Whom a respondent would vote for in a two-way 2024 race between Harris and Trump;
Whom a respondent would vote for in a six-way 2024 race between Harris, Trump, Libertarian candidate Chase Oliver, Green Party candidate Jill Stein, and Independents Robert F. Kennedy Jr. and Cornel West;
Whom a respondent would vote for in a generic congressional race between an unnamed Democrat and Republican;
A respondent’s levels of favorability for Harris and Trump on a five-point scale;
A respondent’s level of approval for Harris’ job performance as vice president on a five-point scale; and
Whether a respondent says they are considering Harris, Trump, a third-party candidate, and/or not voting in 2024.
If a respondent meets three of the four indicators below, they are considered a swing voter.
Their vote choices between 2020 vote recall, the 2024 two-way ballot, and the 2024 six-way ballot are not consistent (e.g., they do not consistently choose Biden/Harris or Trump).
Their vote choices between the 2024 two-way ballot, the 2024 six-way ballot, and generic congressional ballot are not all consistent.
They report similar ratings for Harris favorability and Trump favorability, or for Harris’ job approval and Trump favorability.
They say they are considering at least two options in 2024 (Harris, Trump, third-party, not voting).
As additional controls, we also exclude all voters who say they are "definitely" voting for a certain candidate on the six-way ballot, along with voters who say they will “definitely not vote” at all in the 2024 presidential election.
Methodology: Biden-Trump Swing Voters (OUTDATED)
The 2024 presidential election is unique in several ways. For one, it is a rematch of the 2020 election, the first presidential rematch of its kind since 1956, and this time it's between a current and former president. The two leading candidates have nearly universal name recognition, but they are also both relatively unpopular with voters, and there are also several third-party candidates running who are capturing a higher portion of the vote than they did in the previous election cycle.
Given this dynamic, there are various types of swing voters in the 2024 election: Biden 2020 and Trump 2020 voters who are now considering voting third-party or for the other major party’s candidate, voters who say they’re undecided about whom they’ll vote for, and new or first-time voters who are weighing multiple options, among others. Our scoring method captures various types of swing voters by identifying respondents who show a consistent swing pattern across multiple indicators.
In recent years, analysts have used various methodologies to identify swing voters, including vote-switchers (Biden-to-Trump or Trump-to-Biden), undecided voters, and those who report similar favorability ratings toward the major candidates.
Each of these indicators is useful, but they all have limitations when solely relied on to determine the swing voters of the 2024 election. Below, we discuss how each of these indicators can exclude voters who should be classified as swing voters (false negatives), and may include voters who are actually set on their vote choice (false positives).
Looking exclusively at those who switch their vote from Biden in 2020 to Trump in 2024 (or vice versa), without also considering other swing indicators, is limiting. This methodology does not include Biden or Trump voters who are now choosing a third-party candidate, Biden or Trump voters who say they are undecided this time around, or new or first-time voters. This methodology also includes vote-switchers who are not necessarily persuadable swing voters, such as voters who say they picked Biden or Trump in 2020 but say they are “definitely” voting for the opposite candidate this year.
Looking exclusively at voters who say they are “undecided” about whom they will vote for is also limiting because it does not account for voters who currently lean toward one candidate or the other, but could still change their minds.
Additionally, “double haters” — voters who say they are unfavorable of both Biden and Trump — are not fully representative of swing voters on their own. Voters across party lines have expressed dissatisfaction with both major candidates, and about 1 in 3 voters indicate that their vote this year is driven by opposition to the other candidate, rather than approval of the candidate they support. As a result, many voters may be unfavorable of Biden or Trump but are still certain they will vote for them.
To address the limitations and gaps in these individual metrics, we found that looking at a respondent’s cumulative pattern of responses was most effective at identifying various types of swing voters for the 2024 presidential election.
Our Scoring Method
In our surveys, we asked respondents various questions to create our scoring method. These include:
Whom a respondent voted for in the 2020 presidential election;
Whom a respondent would vote for in a two-way 2024 race between Biden and Trump;
Whom a respondent would vote for in a six-way 2024 race between Biden, Trump, Libertarian candidate Chase Oliver, Green Party candidate Jill Stein, and Independents Robert F. Kennedy Jr. and Cornel West;
Whom a respondent would vote for in a generic congressional race between an unnamed Democrat and Republican;
A respondent’s levels of favorability for Biden and Trump on a five-point scale;
A respondent’s level of approval for Biden’s job performance on a five-point scale; and
Whether a respondent says they are considering Biden, Trump, a third-party candidate, and/or not voting in 2024.
If a respondent meets three of the four indicators below, they are considered a swing voter. (We found that requiring all four indicators to be met was overly restrictive, capturing too few respondents, while requiring just two of the four to be met was overly inclusive, capturing too many).
Their vote choices between 2020 vote recall, the 2024 two-way ballot, and the 2024 six-way ballot are not consistent.
Their vote choices between the 2024 two-way ballot, the 2024 six-way ballot, and generic congressional ballot are not all consistent.
They report similar ratings for Biden favorability and Trump favorability, or for Biden job approval and Trump favorability.
They say they are considering at least two options in 2024 (Biden, Trump, third-party, not voting).
As additional controls, we also exclude all voters who say they are "definitely" voting for a certain candidate on the six-way ballot, along with voters who say they will “definitely not vote” at all in the 2024 presidential election.