Democrats are entering the U.S. midterm elections with high expectations, as the vote is widely seen as crucial to the country’s political future.
A Republican president struggling with low approval ratings, widespread frustration over rising grocery prices and household bills, and increasingly favorable polling have given Democrats reasons to believe they could perform strongly in Tuesday’s elections.
Recent surveys suggest Democratic candidates are competitive in far more than the 218 congressional districts needed to take control of the House of Representatives. Meanwhile, several key Senate races appear to be closely contested, with Democrats either running neck and neck with Republicans or holding narrow advantages.
A recent The New York Times poll, for example, showed the Senate race in South Carolina as essentially tied, despite Donald Trump carrying the state by 18 percentage points in the 2024 presidential election. Other recent CNN polls have indicated Democratic advantages in Texas, Kansas and Maine.
The history of U.S. politics offers several reminders that polling predictions can be inaccurate, even when surveys are conducted just days before voters head to the ballot box. Donald Trump has repeatedly performed better than polling averages suggested. His victories in the 2016 and 2024 presidential elections both exposed weaknesses in how pollsters measured support for his candidacy.
Even in 2020, when Trump narrowly lost to Democrat Joe Biden, most polls had predicted a considerably larger victory for Biden than the final result delivered.
Democrat Abdul El-Sayed, for instance, was expected by some polls to win the Democratic Senate primary in Michigan by a double-digit margin. Instead, his eventual advantage was just one percentage point.
In Wisconsin’s Democratic gubernatorial primary, a candidate who had been leading by nearly 20 points in surveys ultimately lost by a very narrow margin. These examples have renewed questions about whether polling companies are accurately capturing the views and voting intentions of Americans.
According to Clifford Young, president of Ipsos Public Affairs, which conducts political and market research, measuring public opinion has become increasingly difficult in recent years. One major reason is that traditional methods of reaching voters are becoming less effective. Many Americans have abandoned landline telephones, are reluctant to answer calls from unfamiliar numbers and are increasingly unwilling to participate in surveys.
Young believes these changes create particular difficulties when trying to measure conservative support. “Conservatives, particularly those on the far right, are much more anti-establishment. They don’t participate in anything. They hate the system. That’s the challenge,” Young said.
If Republican voters are underrepresented in surveys and polling companies fail to compensate for that imbalance when building their predictive models, the resulting numbers could make Democratic candidates appear stronger than they actually are.
The Challenge of Predicting Who Will Actually Vote
Another major difficulty for pollsters is determining which people will ultimately participate in an election. A person who expresses support for a particular candidate in a survey does not necessarily become an actual voter. This distinction can have a significant impact on election results.
One possible explanation for Trump’s stronger-than-expected performances in previous presidential elections is that many of his supporters, who do not regularly vote, turned out in greater numbers than polling models anticipated.
However, the accuracy of polling has generally improved in recent years when it comes to nationwide midterm elections. One explanation is that Trump, whose political appeal has helped mobilize dissatisfied voters, has not personally been a candidate in these contests.
The 2022 midterms provide an important example. At the time, surveys suggested Democrats could avoid the kind of heavy losses traditionally expected for the party controlling the White House, despite relatively weak approval ratings for then-President Joe Biden.
Democrats eventually lost control of the House of Representatives, but their losses were relatively limited. They also managed to retain their majority in the Senate. Young cautions against treating this year’s primary election results as definitive evidence that polling for the general elections is unreliable.
According to him, primary contests have historically been more difficult to predict because voters often make their decisions about candidates much closer to election day.
Why Democrats Could Still Face an Uphill Battle
American political history has repeatedly shown that the president’s party tends to lose ground during midterm elections. One of the clearest examples came in 2010, when Republicans gained more than 60 seats in the House of Representatives and also made significant progress in the Senate.
At the time, the United States was still struggling to recover from the financial crisis, while conservatives were strongly opposed to healthcare reforms introduced by Democratic President Barack Obama.
Polls anticipated Democratic losses, but they failed to fully capture the scale of the Republican victory. The political circumstances are different this time. Democrats are now the opposition party, while economic concerns remain among the most important issues influencing American voters.
Republican-Friendly Electoral Districts
One important consideration is the political geography of this year’s elections. Many of the districts where competitive races are taking place were comfortably won by Trump in the 2024 presidential election. That gives Republican candidates an initial advantage, even if national polling suggests Democrats are gaining momentum.
Changes to congressional district boundaries over the years have also made it more difficult for either party to flip seats. As a result, fewer districts are genuinely competitive, limiting the number of opportunities Democrats have to translate improvements in national support into additional seats in Congress.
Growing Political Polarization
Another challenge is the increasing polarization of American society. The number of undecided voters and people willing to switch their political allegiance has declined as more Americans become firmly attached to one party.
Some political experts describe the electorate as increasingly entrenched in its existing political positions. This makes it harder for Democrats to attract enough Republican-leaning voters to turn close races in their favor.
Republicans have also benefited from a financial advantage during the campaign, with hundreds of millions of dollars available for negative advertising targeting Democratic candidates in the final weeks before the election. These campaigns can influence how voters perceive candidates, particularly in closely contested races.
Polling Averages Offer a Better Picture Than Individual Surveys
Polling companies attempt to account for these challenges when designing their surveys. Well-constructed polls use statistical models intended to reflect the composition of the electorate and account for factors that could influence participation and voting preferences.
Nevertheless, no survey can eliminate uncertainty entirely. Every poll carries a margin of error, representing the degree of statistical uncertainty associated with the size of the sample compared with the wider population. For this reason, polling averages that combine several surveys are generally considered more reliable than relying on a single poll.
Even if current surveys are wrong by several percentage points, as happened during recent presidential elections, their overall picture still suggests Democrats could perform well on November 3. In last year’s local and special elections, Democratic candidates performed better than many surveys had predicted, largely because their supporters turned out in greater numbers than expected.
Trump’s campaign appearances in the final days before the midterms, particularly in states he had won comfortably in 2024, may also have reinforced Democratic hopes that Republicans are facing difficulties.
However, campaign rallies and polling movements do not necessarily translate into election results. Even with extensive polling data available, the final days of a campaign can introduce another layer of uncertainty.
Voters may reconsider their choices before election day, while undecided voters can sometimes move in large numbers toward the same candidate. This is one reason political analysts caution against treating current polling leads as guarantees of victory.
Ultimately, uncertainty remains an unavoidable part of election forecasting. Young says polling companies are continuing to improve their methods, but understanding how people behave and how they make political decisions remains a significant challenge.
“I believe we’re doing a better job. But part of the problem isn’t just with polling companies. We’re dealing with people, and people aren’t easy to understand,” he said.
For Democrats, the latest surveys offer genuine reasons for optimism as they seek to regain control of Congress. But whether those numbers translate into victories on November 3 will depend on voter turnout, last-minute decisions and the accuracy of the models used to predict the outcome.
