Undecided Voter Statistics at a Glance
Undecided voter statistics are less about a single headline number and more about how quickly preferences harden once people start comparing candidates, parties, and outcomes.
The source data shows a split field in late 2024, with some voters already locked in, many still weighing the race, and a smaller but important group saying they had not yet settled on a preferred candidate (Pew Research Center, Oct. 10, 2024; Pew Research Center topline, Oct. 24, 2024).
Table of contents
- What the latest survey numbers say
- How firm different voter groups were
- Why voters said they lacked a preferred candidate
- How undecided and lean voters broke in polling
- What the numbers suggest about persuasion
- Comparing the sources
- Reading the undecided share correctly
What the latest survey numbers say
The clearest headline from the data is that most registered voters were not treating the 2024 presidential race as settled.
One Pew Research Center measure found that 14% of registered voters said the race was already clear, while 86% said it was not yet clear (Pew Research Center, Oct. 10, 2024). That is a useful reminder that “undecided” is not the same as “uninformed” or “disengaged.” Many people can be thinking carefully without having reached a final answer.
Another Pew topline item measured a narrower category of people who still lacked a preferred candidate. In that question, 14% said they were open to another candidate or undecided (Pew Research Center topline, Oct. 24, 2024). That is a much smaller and more specific slice than the broader group who said the race was not yet clear.
Fast facts
- 14% of registered voters said the race was already clear, while 86% said it was not yet clear (Pew Research Center, Oct. 10, 2024).
- 14% said they were open to another candidate or undecided in the Pew topline question (Pew Research Center topline, Oct. 24, 2024).
- 16% said they did not know enough about the candidates in that same Pew topline item (Pew Research Center topline, Oct. 24, 2024).
- 42% of likely voters in the Reuters/Ipsos October 2024 poll chose Kamala Harris, while 38% chose Donald Trump (Reuters/Ipsos, Oct. 4-7, 2024).
- 7% said they did not know in the Reuters/Ipsos registered-voter question, and 5% said they did not know in the likely-voter question (Reuters/Ipsos, Oct. 4-7, 2024).
The word “undecided” covers several different behaviors: delay, hesitation, indifference, and active comparison.
How firm different voter groups were
The source statistics show a meaningful difference between strong partisans and softer supporters. That matters because undecided voter statistics are often overstated when they are treated as a single pool.
Candidate attention and motivation
Among Pew’s support groups, 72% of certain Trump supporters said they had thought a lot about the candidates, compared with 46% of likely Trump supporters and 42% of lean Trump supporters (Pew Research Center, Oct. 10, 2024). On the other side, 69% of certain Harris supporters had thought a lot about the candidates, compared with 32% of likely Harris supporters and 30% of lean Harris supporters (Pew Research Center, Oct. 10, 2024).
That spread is important because it shows the middle layers of support were still more open than the certain supporters on both sides.
Motivation to vote
The same pattern appears in motivation. Pew found that 70% of certain Trump supporters were extremely motivated to vote, while only 26% of likely Trump supporters and 11% of lean Trump supporters said the same (Pew Research Center, Oct. 10, 2024).
For Harris supporters, 70% of certain Harris supporters were extremely motivated to vote, compared with 21% of likely Harris supporters and 12% of lean Harris supporters (Pew Research Center, Oct. 10, 2024).
That is a strong signal that “lean” and “likely” are not interchangeable with “certain.” The lower the certainty, the lower the intensity.
Comparison table
| Group | Thought a lot about candidates | Extremely motivated to vote |
|---|---|---|
| Certain Trump supporters | 72% (Pew Research Center, Oct. 10, 2024) | 70% (Pew Research Center, Oct. 10, 2024) |
| Likely Trump supporters | 46% (Pew Research Center, Oct. 10, 2024) | 26% (Pew Research Center, Oct. 10, 2024) |
| Lean Trump supporters | 42% (Pew Research Center, Oct. 10, 2024) | 11% (Pew Research Center, Oct. 10, 2024) |
| Certain Harris supporters | 69% (Pew Research Center, Oct. 10, 2024) | 70% (Pew Research Center, Oct. 10, 2024) |
| Likely Harris supporters | 32% (Pew Research Center, Oct. 10, 2024) | 21% (Pew Research Center, Oct. 10, 2024) |
| Lean Harris supporters | 30% (Pew Research Center, Oct. 10, 2024) | 12% (Pew Research Center, Oct. 10, 2024) |
Why voters said they lacked a preferred candidate
The topline Pew item offers a more direct look at why some people were still undecided or open.
The largest reason in that question was that 20% cited specific policy disagreement as a reason for lacking a preferred candidate (Pew Research Center topline, Oct. 24, 2024). Another 16% said they did not know enough about the candidates (Pew Research Center topline, Oct. 24, 2024).
A separate 14% said they were open to another candidate or undecided, while 10% said more information might come out later (Pew Research Center topline, Oct. 24, 2024). These are not the same kind of uncertainty. One group is still weighing policy; another is waiting for more evidence; another is simply not ready to choose.
Reason breakdown
| Reason for lacking a preferred candidate | Share |
|---|---|
| Specific policy disagreement | 20% (Pew Research Center topline, Oct. 24, 2024) |
| Did not know enough about candidates | 16% (Pew Research Center topline, Oct. 24, 2024) |
| Open to another candidate or undecided | 14% (Pew Research Center topline, Oct. 24, 2024) |
| More information might come out later | 10% (Pew Research Center topline, Oct. 24, 2024) |
| Other | 15% (Pew Research Center topline, Oct. 24, 2024) |
| No answer | 16% (Pew Research Center topline, Oct. 24, 2024) |
| General dislike of the selected candidate | 1% (Pew Research Center topline, Oct. 24, 2024) |
| Negative view of a candidate’s experience in office | 2% (Pew Research Center topline, Oct. 24, 2024) |
The “Other” and “No answer” shares are also telling. Together, they account for a substantial amount of uncertainty that does not map neatly onto a simple story about ideology or candidate quality (Pew Research Center topline, Oct. 24, 2024).
The smallest reasons mattered less than the biggest ones
Only 1% cited general dislike of the selected candidate in the current wave, and 2% cited a negative view of a candidate’s experience in office in both waves (Pew Research Center topline, Oct. 24, 2024). By comparison, policy disagreement and knowledge gaps were much more common. That suggests the undecided pool was being shaped more by evaluation and information than by pure rejection.
How undecided and lean voters broke in polling
The Reuters/Ipsos and ABC/Ipsos numbers show how undecided or near-undecided voters can move once a question forces a choice.
In the Reuters/Ipsos October 2024 poll, 42% of likely voters chose Harris and 38% chose Trump, while 7% said they did not know (Reuters/Ipsos, Oct. 4-7, 2024). In the registered-voter version, 38% chose Trump, 4% were skipped in the ballot item, 3% chose some other candidate, and 9% said they would not vote (Reuters/Ipsos, Oct. 4-7, 2024).
The lean question narrowed the field further. Among likely voters, 48% picked Harris after forced choice, 47% picked Trump after forced choice, and 4% skipped the question (Reuters/Ipsos, Oct. 4-7, 2024). That is a near-even split once respondents were pushed toward a binary response.
ABC/Ipsos showed a similar pattern. On Oct. 8, 2024, 50% said Harris in the forced-choice vote preference excluding would-not-vote responses, 49% said Trump, and 1% chose someone else (ABC News/Ipsos, Oct. 8, 2024). In the same dataset, 83% of registered voters in the undecided-or-skipped question said they would not vote if those were the only candidates (ABC News/Ipsos, Oct. 8, 2024).
That last figure is especially useful because it separates nonparticipation from preference. A person who is undecided is not always searching for a candidate; sometimes they are signaling that the ballot question does not fit their intent.
Polling signals side by side
| Poll item | Harris | Trump | Other / unknown / skipped |
|---|---|---|---|
| Reuters/Ipsos likely voters ballot item | 42% (Reuters/Ipsos, Oct. 4-7, 2024) | 38% (Reuters/Ipsos, Oct. 4-7, 2024) | 5% did not know, 3% some other candidate (Reuters/Ipsos, Oct. 4-7, 2024) |
| Reuters/Ipsos likely voters lean forced choice | 48% (Reuters/Ipsos, Oct. 4-7, 2024) | 47% (Reuters/Ipsos, Oct. 4-7, 2024) | 4% skipped (Reuters/Ipsos, Oct. 4-7, 2024) |
| ABC/Ipsos forced-choice excluding would-not-vote responses | 50% (ABC News/Ipsos, Oct. 8, 2024) | 49% (ABC News/Ipsos, Oct. 8, 2024) | 1% someone else (ABC News/Ipsos, Oct. 8, 2024) |
What the numbers suggest about persuasion
The data does not support a single, oversized undecided bloc waiting to be persuaded by one message. Instead, it points to several smaller groups with different reasons for hesitation.
Some voters needed more issue clarity. Some were still information-seeking. Some had not moved from a general openness to a committed choice. And some were captured in poll categories that resemble nonresponse or nonparticipation more than genuine indecision (Pew Research Center topline, Oct. 24, 2024; Reuters/Ipsos, Oct. 4-7, 2024; ABC News/Ipsos, Oct. 8, 2024).
The motivation and attention figures reinforce that idea. Certain supporters on both sides were much more engaged than lean supporters, which means the persuadable zone was concentrated in the softer layers of support, not spread evenly across the electorate (Pew Research Center, Oct. 10, 2024).
Practical reading of the data
- Strong support and high motivation travel together.
- Lean support often comes with lower attention and lower certainty.
- “Undecided” can include issue disagreement, information gaps, temporary hesitation, and refusal to answer.
- Forced-choice polls can compress that complexity into a near tie.
Comparing the sources
The three source sets answer different questions, so they should not be treated as duplicates.
Pew Research Center’s Oct. 10, 2024 data is best for understanding strength of support, candidate attention, and motivation (Pew Research Center, Oct. 10, 2024).
Pew’s Oct. 24, 2024 topline is best for reasons people lacked a preferred candidate, especially policy disagreement and knowledge gaps (Pew Research Center topline, Oct. 24, 2024).
Reuters/Ipsos and ABC/Ipsos are best for showing how responses change under ballot-style or forced-choice wording (Reuters/Ipsos, Oct. 4-7, 2024; ABC News/Ipsos, Oct. 8, 2024).
Source-by-source takeaway
| Source | Best use | Main signal |
|---|---|---|
| Pew Research Center, Oct. 10, 2024 | Support intensity and motivation | Certain supporters were far more engaged than lean supporters |
| Pew Research Center topline, Oct. 24, 2024 | Reasons for no preferred candidate | Policy disagreement and knowledge gaps were the biggest reasons |
| Reuters/Ipsos, Oct. 4-7, 2024 | Ballot and lean behavior | The race tightens under forced choice |
| ABC News/Ipsos, Oct. 8, 2024 | Forced-choice comparison | Harris and Trump were nearly even after excluding would-not-vote responses |
Reading the undecided share correctly
A useful way to interpret undecided voter statistics is to stop treating them as a single bucket.
The source data points to at least four distinct groups: people who are still evaluating, people who are waiting for more information, people who are leaning but not committed, and people who are effectively outside the choice set because they would not vote or did not respond in a standard way (Pew Research Center topline, Oct. 24, 2024; Reuters/Ipsos, Oct. 4-7, 2024; ABC News/Ipsos, Oct. 8, 2024).
That distinction matters because it changes what the numbers can tell you. A 14% undecided share is not a simple pool of persuadable voters. It is a mixed group with different thresholds for commitment, different levels of attention, and different reasons for hesitation.
The broader lesson from the data is straightforward: the closer a voter is to certainty, the more likely they are to have thought hard about the candidates and to be highly motivated to vote (Pew Research Center, Oct. 10, 2024).