Dozens of polls were released in the lead up to Maine’s June primary election, and more are starting to come out as races heat up ahead of the general election in November, each one attempting to measure the beliefs of voters across the state.
Polls have faced growing criticism in recent years, and their results can sometimes be misunderstood. It’s worth taking a closer look at how they work, how they are conducted in Maine and what they can tell us about voters’ priorities.
What is an election poll?
The political polls that typically get the most media coverage are “horse race” polls that attempt to illustrate which candidate is ahead in a particular race. But election polls can do more than forecast election outcomes. Polls are also used by campaigns to test messaging, shape strategy and understand which issues are top of mind for voters, as well as how and when people are planning on casting their vote.
While election polls are conducted like many other surveys, there is one key difference: they are attempting to describe the views of voters, which means they have to figure out who is likely to cast a ballot. This can be difficult, particularly in high-turnout election years, when people who don’t typically vote show up on Election Day.
How are election polls conducted?
Pollsters need a group of people to interview, a set of questions and a way to interview the people who have been selected.
Choosing who to interview, according to the nonpartisan Pew Research Center, is the “single most important factor determining how accurate the poll will be.” Pollsters may select participants at random or survey people who have either opted-in or who a pollster has selected from a specific group.
The first method, called random sampling, involves randomly contacting potential participants, such as pulling from a list of residential addresses provided by the U.S. Postal Service or calling numbers generated by a computer.
In the second method, pollsters rely on people choosing to participate, perhaps after they have seen an ad on social media or received a survey via text message. They may also contact people via databases maintained by companies such as YouGov or Ipsos that list people who have volunteered to take surveys in exchange for small incentives.
Once a pollster has selected a group of people to survey, they must determine how to reach them. The way a poll is conducted — over the phone, in-person or online — may depend in part on how participants were selected. Throughout the early 2000s, telephone polling, via landlines, was the dominant way to conduct surveys, according to Pew. Because of declining response rates and increasing costs, some pollsters are now turning to other modes of polling, such as sending online surveys through email or text.
Who conducts election polls in Maine?
Election polls are either conducted and published for the general public or conducted internally on behalf of campaigns or partisan organizations. Public polls offer citizens information about both candidates’ chances and voter trends. Private polling is done to inform campaign strategy by collecting voter preferences and demographic trends, and by testing what phrases or policy ideas resonate with voters. These latter polls are typically only released when it is beneficial to a campaign’s cause.
Some polls are more credible than others. The New York Times evaluates pollsters based on the following criteria:
- Has a track record of accuracy in recent elections
- Is a member of a professional polling organization
- Conducts probability-based sampling
Groups that meet at least two of the three criteria are considered “select pollsters” as long as they are conducting polls for nonpartisan sponsors.
There are a number of research firms, universities and other groups that conduct public and private polls in Maine. Here are lists of the polls that have been conducted on Maine’s U.S. Senate and governor races this election season:
What are the particular challenges to polling in Maine?
Maine is a challenging place to poll for several reasons, according to experts The Monitor spoke to. It has a large portion of independent voters, roughly 29 percent, who are allowed to vote in the state’s semi-open primaries. Maine also employs ranked-choice voting, which can complicate polling.
Independent voters are particularly difficult to predict and account for in surveys because they do not consistently vote along partisan lines like many Democrats or Republicans. As a result, pollsters have a harder time generalizing from past voting patterns and estimating turnout among these voters.
The state’s semi-open primaries, which allow independent voters to participate in either party’s primary, also complicate polling estimates. Because these voters can switch which party’s primary they vote in from one election to the next, their behavior is more difficult for pollsters to predict.
Maine is one of just two states that uses ranked-choice voting for statewide elections. Because ranked-choice voting divides a sample into many subgroups, it leads to a larger margin of error. Pollsters are also still discovering how to account for candidates cross-endorsing one another, something several candidates in Maine did during the 2026 primaries.
“There haven’t been a lot of ranked-choice elections in the country and it’s difficult to tease out how much of an effect that has on polling,” said Sean McKinley, project director at the University of New Hampshire Survey Center.
Are election polls accurate?
Polls can differ in many ways, including how pollsters select participants, what questions they ask, how those questions are worded, and how they adjust their results to better reflect the population. All of these choices influence a poll’s findings.
Pollsters use data weighting to ensure that their results reflect the demographics of the broader electorate, not just those willing to take a poll, by giving more weight to groups that are underrepresented among their sample. Different weighting choices can produce different results.
The uncertainty of a poll is reflected in its margin of error, which estimates how closely the survey results are likely to match the views of the entire population. When the difference between candidates falls within the margin of error, the race is generally considered too close to call based on that poll alone.
Pollsters were heavily criticized after the 2016 and 2020 general elections. In Maine, Sara Gideon, the former speaker of the Maine House of Representatives, led U.S. Sen. Susan Collins in every single public poll, but eventually lost to Collins by nine points. Nationally, pollsters generally underestimated support for President Donald Trump, particularly in key battleground states.
The polling error in 2020, according to an analysis by the American Association of Public Opinion Research, a professional organization of public opinion professionals, was “of an unusual magnitude,” the highest in 40 years for the national popular vote.
The errors in 2016, according to AAPOR, could be attributed in part to voters changing their minds in key states during the final week of the campaign and to a failure of pollsters to account for the over-representation of college graduates in their data.
Since then, pollsters have revised their methods, but polling remains, said Mark Brewer, a political science professor at the University of Maine, “as much art as it is science.”
Fitzgerald Reporting Fellow Kate Kaufman contributed reporting.
