© 2026 ABC News

Are partisan pollsters biasing our averages?

One question that we sometimes get is whether polling averages like 538's are biased toward Trump because of the influx of polls conducted by Republican-aligned firms. Over the past two weeks, 22 of the 113 presidential polls released in the seven main swing states were from a Republican pollster or sponsor, while none were from Democratic organizations.** (The remaining 91 polls were nonpartisan.)

While there is always uncertainty about how accurate state polls are, partisan polls affecting our averages is not one of my bigger concerns. That's because we work hard to subtract potential statistical bias from each poll before putting it into our averages. As you can see in our polling-average methodology, we adjust partisan polls to account for the fact that these polls are typically a bit too good for the sponsoring party.

And even for nonpartisan polls, we apply something called a \"house effects\" adjustment that accounts for how much more Democratic- or Republican-leaning a pollster is than its peers (whether due to the partisan leanings of its principals or, simply methodological choices that typically produce more liberal or conservative samples). For example, if a pollster's polls have consistently been 2 points better for Trump than the polling average, after controlling for factors such as a poll's population (likely voters versus registered voters or all adults) and mode (e.g., live phone, online panel, text message, etc.), we adjust those polls 2 points toward Harris.

Finally, we give less weight to polls from pollsters without a 538 pollster rating and pollsters that release a bunch of polls in a short period of time. This ensures that pollsters that are \"flooding the zone\" with polls don't have outsized influence in our averages.

One test for whether these adjustments are working correctly is to see how 538's averages would look if we didn't include any polls from the firms alleged to be trying to influence the averages. The table below shows the results of this comparison. In the second column, you'll find 538's averages as of 4 p.m. Eastern on Oct. 18. The third column is what our averages would have been at that time if we removed those polls but otherwise ran the same algorithm we normally do:

As the table shows, this does not significantly change our averages. In most places, the pollsters in question are indeed more pro-Trump than other pollsters. However, this has just a mild effect on our averages, moving them toward Trump by just 0.3 points on average. (The biggest difference is in Pennsylvania, where our published average gives Harris a 0.1-point lead over Trump, but the nonpartisan average gives her a 0.9-point edge.) That's not a significant difference in a world where the average polling error in presidential elections is 4.3 points, and it's small enough that it could easily be attributed to sampling error or some methodological factor other than partisan bias. As a point of comparison, our averages regularly move by 0.1-0.3 points on a daily basis, and we don't recommend that anyone read into those shifts.

Granted, this says nothing about the motivations of the firms (we like to stick to the data here at 538) or what's going on behind the scenes (we don't really know). What we can say is that, over the long run, polling averages that are more inclusive have typically overperformed averages that use a more restricted set of pollsters or an inconsistent methodology for weighting and making adjustments. One of the reasons we have all the rules and methods we do is to have trust in our work even when we have doubts; that means sticking to our rules even when we may be tempted to make an exception.

Importantly, though, that doesn't mean that we should consume all polls without criticism or taking a closer look at how pollsters are generating their data. In this case, our empirical look at how our averages are operating is reassuring us that things are working as intended.

What if the election were held today?

In conclusion, the presidential race is close no matter which way you slice it. This is both because the polls are exceedingly tight right now and because there is still uncertainty about how the final two and a half weeks of the campaign will unfold. As we have written, the race can change quickly in the final weeks. For example, in the last few weeks of the 2016 and 2020 campaigns, polls moved by about 4 and 2 points, respectively, toward Trump.

The value our forecast adds over our polling averages is that it attempts to quantify how likely such a shift is — and how inaccurate polls might be even on Election Day itself. But this also means that as the time remaining for people to change their minds decreases, the forecast's uncertainty about the race also decreases — and very quickly.

But because the polls are so tight right now, if they don't budge, the forecast won't either. If you run our presidential election forecast in \"nowcast\" mode — where we pretend the election is being held today and remove all volatility stemming from how many days are left until Nov. 5 — Trump still has a 52-in-100 chance of winning.

Finally, I have to remind you that a close election in terms of the odds does not necessarily mean that the final outcome will be close. If the polls miss by a historically normal amount, either candidate could easily win with 300 Electoral College votes. While we can say that this is one of the closest elections in modern history in the polls, we can't guarantee that it will go into the history books as one of the closest in terms of votes.

Mary Radcliffe contributed research.

CORRECTION AND CLARIFICATION (Oct. 29, 2024, 12:50 p.m. Eastern): This article originally said that over the previous two weeks, 23 of the 121 polls released in the seven main swing states were from a Republican pollster or sponsor, while four were from Democratic organizations and the remaining 93 were nonpartisan. The number of nonpartisan polls was actually 94. Those numbers also included polls of Senate and House races. Because the focus of this article is the presidential race, those numbers have been updated to reflect numbers only among presidential polls.

Footnotes

*All numbers in this article as of Oct. 18 at 4 p.m. Eastern.

**Includes all polls added to our database from Oct. 5 to Oct. 18 at 4 p.m. Eastern. Partisan polls are defined as polls from a pollster or sponsor marked as partisan in our database, including internal polls conducted for a campaign.

","canonicalUrl":"https://abcnews.com/538/trump-gained-538s-forecast-election-toss/story?id=114907042","legacySlug":"/news/story/trump-gained-538s-forecast-election-toss-114907042","noIndexNoFollow":false},"publishTime":"20:00","publishDate":"10-18-2024","updatedTime":"16:50","updatedDate":"10-29-2024","socialImage":{"alt":"A 538 Election Update for Friday, Oct. 18.","credit":"ABC News, Getty Images","ratio":"16x9","url":"https://s.abcnews.com/images/538/CloseElectionPoll_v01_LY_1729275893773_hpMain_16x9_1600.jpg","width":992,"height":558},"datePublished":"10/18/2024 20:00:00 GMT","video":{"live":false,"id":114907042,"headline":"538 forecast: Trump gains, race still a toss-up","mediaAssetTitle":"ELECTION-UPDATE","description":"No matter what polls you look at, the 2024 election is super close.","duration":"2:35","posterImg":{"url":"https://s.abcnews.com/images/GMA/default-img-undefined.png","width":608,"height":342},"video":{"feed":"https://service-pkgabcnews.akamaized.net/opp/hls/abcnews/2024/10/241015_538_PoliticsPod_polling_ruth_clip1_,500,800,1200,1800,2500,3200,4500,.mp4.csmil/playlist.m3u8"},"playlist":["132055565","131830882","130993584"]},"relatedItems":[{"contentType":"video","date":"April 15, 2026","headline":"American influencer found dead in Tanzania","section":"News","slug":"/video/132055565","id":"132055565","image":{"alt":"VIDEO: American influencer found dead in Tanzania","credit":"ABCNews.com","ratio":"1x1","url":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_1x1_608.jpg","width":384,"height":384},"images":{"alt":"VIDEO: American influencer found dead in Tanzania","credit":"ABCNews.com","crops":[{"16x9":{"small":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_16x9_608.jpg","medium":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_16x9_992.jpg","large":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_16x9_1600.jpg"}},{"9x16":{"small":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_9x16_608.jpg","medium":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_9x16_992.jpg","large":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_16x9_1600.jpg"}},{"1x1":{"small":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_1x1_608.jpg","medium":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_1x1_992.jpg","large":"https://s.abcnews.com/images/GMA/260415_gma_norwood_ashlee2_732_hpMain_1x1_1600.jpg"}}]}},{"contentType":"video","date":"April 8, 2026","headline":"Ceasefire analysis, unanswered questions ahead","section":"News","slug":"/video/131830882","id":"131830882","image":{"alt":"VIDEO: Ceasefire analysis, unanswered questions ahead","credit":"ABCNews.com","ratio":"1x1","url":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_1x1_608.jpg","width":384,"height":384},"images":{"alt":"VIDEO: Ceasefire analysis, unanswered questions ahead","credit":"ABCNews.com","crops":[{"16x9":{"small":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_16x9_608.jpg","medium":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_16x9_992.jpg","large":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_16x9_1600.jpg"}},{"9x16":{"small":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_9x16_608.jpg","medium":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_9x16_992.jpg","large":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_16x9_1600.jpg"}},{"1x1":{"small":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_1x1_608.jpg","medium":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_1x1_992.jpg","large":"https://s.abcnews.com/images/GMA/260408_gma_krl1_hpMain_1x1_1600.jpg"}}]}},{"contentType":"video","date":"March 12, 2026","headline":"Winter whiplash plunges temperatures along the East Coast","section":"News","slug":"/video/130993584","id":"130993584","image":{"alt":"VIDEO: Winter whiplash plunges temperatures along the East Coast","credit":"ABCNews.com","ratio":"1x1","url":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_1x1_608.jpg","width":384,"height":384},"images":{"alt":"VIDEO: Winter whiplash plunges temperatures along the East Coast","credit":"ABCNews.com","crops":[{"16x9":{"small":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_16x9_608.jpg","medium":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_16x9_992.jpg","large":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_16x9_1600.jpg"}},{"9x16":{"small":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_9x16_608.jpg","medium":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_9x16_992.jpg","large":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_16x9_1600.jpg"}},{"1x1":{"small":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_1x1_608.jpg","medium":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_1x1_992.jpg","large":"https://s.abcnews.com/images/GMA/260312_gma_zee_storm2_hpMain_1x1_1600.jpg"}}]}}],"relatedContentSection":"news","schemaContent":{"name":"538 forecast: Trump gains, race still a toss-up","description":"No matter what polls you look at, the 2024 election is super close.","duration":"2:35","uploadDate":"10-18-2024","publication":"10-18-2024","images":"https://s.abcnews.com/images/GMA/default-img-undefined.png","url":"https://service-pkgabcnews.akamaized.net/opp/hls/abcnews/2024/10/241015_538_PoliticsPod_polling_ruth_clip1_,500,800,1200,1800,2500,3200,4500,.mp4.csmil/playlist.m3u8","contentUrl":"https://service-pkgabcnews.akamaized.net/opp/hls/abcnews/2024/10/241015_538_PoliticsPod_polling_ruth_clip1_,500,800,1200,1800,2500,3200,4500,.mp4.csmil/playlist.m3u8","link":"https://www.goodmorningamerica.com/news/story/trump-gained-538s-forecast-election-toss-114907042"}},"playlist":[{"id":"132054443","contentType":"story","section":"news"},{"id":"132054798","contentType":"story","section":"news"},{"id":"132033010","contentType":"story","section":"news"},{"id":"131912713","contentType":"story","section":"news"},{"id":"131830583","contentType":"story","section":"news"},{"id":"131834976","contentType":"story","section":"news"},{"id":"131554765","contentType":"story","section":"news"},{"id":"131554815","contentType":"story","section":"news"},{"id":"131543053","contentType":"story","section":"news"},{"id":"131432442","contentType":"story","section":"news"},{"id":"131121474","contentType":"story","section":"news"},{"id":"131247079","contentType":"story","section":"news"},{"id":"131228784","contentType":"story","section":"news"},{"id":"131178806","contentType":"story","section":"news"},{"id":"131142257","contentType":"story","section":"news"},{"id":"131046664","contentType":"story","section":"news"},{"id":"131048076","contentType":"story","section":"news"},{"id":"131033212","contentType":"story","section":"news"},{"id":"130999943","contentType":"story","section":"news"},{"id":"130971027","contentType":"story","section":"news"}],"kvps":{"pgtyp":"article","lang":"en","sp":"goodmorningamerica","programmatic":"true","bundleId":"com.abcnews"}},"analytics":{"accountID":"wdgnewwdgnewgmaweb","ns":"gma","pageName":"gma:news:video","pageType":"video","globalSpecVersion":"v1.08","siteDifferentiator":"gma:site","tagID":"g_page01","userABCookie":"0","section":"news","title":"538 forecast: Trump gains, race still a toss-up","pubTime":"16:00","pubDate":"10-18-2024","modTime":"12:50","modDate":"10-29-2024","taxonomyTags":"none","id":114907042,"editorialOtherSubjects":"","wordCount":"none","columns":"none","authors":"","authorsUnit":"none","authorsBureau":"none","subBrand":"Good Morning America","provider":"Good Morning America","videoName":"538 forecast: Trump gains, race still a toss-up","mediaAssetTitle":"ELECTION-UPDATE","videoId":114907042,"mediaOnPage":"video","legacySlug":"/news/story/trump-gained-538s-forecast-election-toss-114907042"},"taboola":{}},"request":{"headers":{},"httpVersion":"1.1","method":"GET","url":"/video/114907042","vary":{"host":"www.goodmorningamerica.com","cached":true,"path":"/video/114907042","forwarded-proto":"https","device":"desktop","userab":"0"}},"viewport":{"width":1260,"height":0},"user":{}};