House effects · 242 shops, 5+ historical polls1998–2026
House effects
Historical Democratic or Republican overstatement, reduced toward zero for smaller samples.
0 mixed-contest histories are not comparable on a D/R scale. See every pollster’s record →
House effects explorer
242 of 242 matching · 242 comparable pollsters
9,348 eligible polls in the matching histories
Cycle filters include shops with at least one represented cycle in the selected range.
Nielson Brothers Polling11 polls · 4 cycles · 2010–2020
Back to filters ↑D+5.86Ascend Action6 polls · 1 cycle · 2022
D+4.99SurveyMonkey255 polls · 4 cycles · 2016–2020
D+4.93Swayable68 polls · 1 cycle · 2020
D+4.37PSB Research19 polls · 3 cycles · 1998–2010
D+4.26SoonerPoll.com22 polls · 10 cycles · 2004–2022
D+4.20Opinion Research Associates14 polls · 5 cycles · 2000–2014
D+4.11RMG Research26 polls · 2 cycles · 2020–2024
D+3.99FM3 Research11 polls · 6 cycles · 1998–2022
D+3.81University of Wyoming Survey & Analysis Center5 polls · 2 cycles · 2020–2022
D+3.59Citizen Data12 polls · 1 cycle · 2020
D+3.52Civiqs39 polls · 2 cycles · 2020–2022
D+3.41Morning Consult89 polls · 5 cycles · 2016–2024
D+3.28SSRS30 polls · 6 cycles · 1998–2022
D+3.12Hays Research Group5 polls · 2 cycles · 2006–2008
D+3.10Change Research101 polls · 3 cycles · 2017–2020
D+3.07Hendrix College17 polls · 5 cycles · 2010–2022
D+3.01Greg Smith & Associates5 polls · 3 cycles · 2002–2010
D+2.98Montana State University Billings Mountain States Poll11 polls · 3 cycles · 2000–2020
D+2.98Global Strategy Group26 polls · 8 cycles · 2004–2022
D+2.97RABA Research7 polls · 5 cycles · 2016–2024
D+2.97Mellman Group28 polls · 8 cycles · 2002–2020
D+2.92GQR59 polls · 13 cycles · 2000–2025
D+2.89Saint Leo University Polling Institute6 polls · 3 cycles · 2014–2018
D+2.83Alaska Survey Research11 polls · 5 cycles · 2004–2022
D+2.72Amber Integrated8 polls · 2 cycles · 2020–2022
D+2.72EMC Research13 polls · 7 cycles · 2000–2020
D+2.69Colby College6 polls · 1 cycle · 2020
D+2.65Ed Renwick/Loyola University New Orleans9 polls · 5 cycles · 2002–2008
D+2.65Garin-Hart-Yang Research Group33 polls · 10 cycles · 1998–2022
D+2.59Lucid25 polls · 2 cycles · 2016–2018
D+2.56St. Cloud State University16 polls · 10 cycles · 2000–2022
D+2.55DFM Research10 polls · 4 cycles · 2008–2018
D+2.47Monmouth University85 polls · 16 cycles · 2000–2021
D+2.45Loras College Public Opinion Survey Center14 polls · 2 cycles · 2014–2016
D+2.37Redfield & Wilton Strategies32 polls · 2 cycles · 2020–2024
D+2.36University of New Hampshire Survey Center116 polls · 13 cycles · 2000–2022
D+2.31Benenson Strategy Group12 polls · 6 cycles · 2006–2022
D+2.29Franklin Pierce University Marlin Fitzwater Center for Communication12 polls · 3 cycles · 2000–2004
D+2.24Minneapolis Star Tribune12 polls · 4 cycles · 2000–2006
D+2.21University of Wisconsin Survey Center7 polls · 5 cycles · 2000–2008
D+2.21Braun Research6 polls · 3 cycles · 2010–2016
D+2.18The Political Matrix/The Listener Group11 polls · 3 cycles · 2018–2022
D+2.16University of North Florida Public Opinion Research Lab10 polls · 5 cycles · 2004–2022
D+2.16Ipsos106 polls · 13 cycles · 2002–2024
D+2.08DCCC Targeting and Analytics Department8 polls · 3 cycles · 2016–2022
D+2.03Impact Research21 polls · 8 cycles · 2004–2022
D+2.02Strategies 3609 polls · 3 cycles · 2012–2020
D+2.01Landmark Communications/Rosetta Stone Communications8 polls · 1 cycle · 2016
D+1.99Wiese Research Associates7 polls · 2 cycles · 2010–2012
D+1.98Arizona State University Morrison Institute for Public Policy6 polls · 5 cycles · 2000–2008
D+1.95The Winston Group11 polls · 7 cycles · 2004–2022
D+1.95Big Ten10 polls · 1 cycle · 2008
D+1.93Cygnal41 polls · 8 cycles · 2014–2024
D+1.92Y2 Analytics7 polls · 2 cycles · 2016–2020
D+1.87Frank N. Magid Associates Inc.5 polls · 1 cycle · 2002
D+1.86GBAO13 polls · 4 cycles · 2012–2020
D+1.83Behavior Research Center (Rocky Mountain Poll)6 polls · 3 cycles · 1998–2008
D+1.77Univision/Latino Decisions/North Star Opinion Research6 polls · 1 cycle · 2020
D+1.76Columbus Dispatch17 polls · 10 cycles · 1998–2016
D+1.74Data for Progress79 polls · 4 cycles · 2019–2024
D+1.73East Carolina University Center for Survey Research13 polls · 3 cycles · 2020–2024
D+1.63Normington, Petts & Associates12 polls · 7 cycles · 2002–2020
D+1.63RT Strategies45 polls · 1 cycle · 2006
D+1.63University of Arkansas Department of Political Science9 polls · 6 cycles · 2004–2022
D+1.61Becker Institute5 polls · 2 cycles · 1998–2002
D+1.54Gravis Marketing/Kaplan Strategies126 polls · 7 cycles · 2012–2020
D+1.52University of Minnesota Hubert H. Humphrey School of Public Affairs8 polls · 4 cycles · 2004–2010
D+1.51Targoz Market Research24 polls · 5 cycles · 2018–2022
D+1.49Abt Associates12 polls · 6 cycles · 2004–2017
D+1.48Beacon Research/Shaw & Co. Research46 polls · 10 cycles · 2012–2025
D+1.48Stockton University12 polls · 7 cycles · 2013–2021
D+1.48Pan Atlantic Research15 polls · 5 cycles · 2000–2014
D+1.47Research 2000248 polls · 9 cycles · 2000–2010
D+1.43Valley Research8 polls · 3 cycles · 1998–2004
D+1.43Focaldata7 polls · 1 cycle · 2024
D+1.42Pew Research Center25 polls · 10 cycles · 1998–2016
D+1.41University of Southern California Center for Economic and Social Research10 polls · 3 cycles · 2016–2020
D+1.41Marketing Workshop8 polls · 3 cycles · 1998–2002
D+1.39Remington Research Group52 polls · 6 cycles · 2012–2022
D+1.39Clarity Campaign Labs16 polls · 7 cycles · 2012–2025
D+1.37Dan Jones & Associates35 polls · 8 cycles · 2002–2016
D+1.34Dittman Research9 polls · 4 cycles · 2006–2022
D+1.32Elway Research20 polls · 9 cycles · 2000–2016
D+1.28Harstad Strategic Research11 polls · 6 cycles · 2002–2014
D+1.28Lake Research Partners12 polls · 6 cycles · 2006–2020
D+1.27The New York Times/Siena College101 polls · 6 cycles · 2016–2024
D+1.22Hart Research Associates/Public Opinion Strategies30 polls · 13 cycles · 1998–2022
D+1.16Mitchell Research & Communications54 polls · 12 cycles · 1998–2024
D+1.16Pharos Research Group33 polls · 1 cycle · 2012
D+1.15HarrisX10 polls · 1 cycle · 2024
D+1.11Landmark Communications37 polls · 6 cycles · 2010–2022
D+1.11Glengariff Group13 polls · 7 cycles · 2010–2024
D+1.06Franklin & Marshall College23 polls · 11 cycles · 2004–2024
D+1.04Florida Atlantic University5 polls · 3 cycles · 2016–2020
D+1.01YouGov447 polls · 14 cycles · 2004–2025
D+1.01ABC News/The Washington Post77 polls · 17 cycles · 1998–2022
D+1.00Public Policy Polling333 polls · 11 cycles · 2008–2022
D+0.99SEA Polling & Strategic Design10 polls · 6 cycles · 2002–2018
D+0.99University of Massachusetts Lowell Center for Public Opinion21 polls · 6 cycles · 2012–2022
D+0.97Elon University9 polls · 5 cycles · 2008–2024
D+0.95The Florida Poll5 polls · 4 cycles · 2000–2010
D+0.9020/20 Insight5 polls · 3 cycles · 2012–2018
D+0.86Frederick Polls7 polls · 3 cycles · 2012–2022
D+0.86Kiley & Company5 polls · 3 cycles · 2010–2014
D+0.86Grove Insight29 polls · 4 cycles · 2006–2012
D+0.85Christopher Newport University Wason Center for Civic Leadership15 polls · 9 cycles · 2010–2025
D+0.83Princeton Survey Research Associates International33 polls · 8 cycles · 2000–2014
D+0.81Harper Polling11 polls · 5 cycles · 2013–2020
D+0.71The Washington Post/George Mason University Schar School of Policy and Government19 polls · 7 cycles · 2016–2025
D+0.71Research Co.63 polls · 6 cycles · 2018–2025
D+0.67Rutgers University Eagleton Center for Public Interest Polling17 polls · 12 cycles · 2000–2021
D+0.61Suffolk University67 polls · 17 cycles · 2002–2025
D+0.61Quinnipiac University172 polls · 20 cycles · 1998–2025
D+0.60ActiVote8 polls · 1 cycle · 2024
D+0.58Strategic Research Associates5 polls · 1 cycle · 2018
D+0.58Marketing Resource Group (MRG)6 polls · 4 cycles · 2000–2018
D+0.56Selzer & Co.36 polls · 14 cycles · 1998–2024
D+0.55University of New Orleans Survey Research Center12 polls · 9 cycles · 1999–2020
D+0.55Vox Populi Polling19 polls · 3 cycles · 2014–2018
D+0.55Susquehanna Polling & Research Inc.47 polls · 10 cycles · 2006–2024
D+0.52University of Georgia School of Public and International Affairs7 polls · 4 cycles · 2018–2024
D+0.50Marquette University Law School12 polls · 7 cycles · 2012–2024
D+0.48Marist College137 polls · 15 cycles · 1998–2024
D+0.47Victory Research10 polls · 4 cycles · 2004–2020
D+0.45CBS News/The New York Times53 polls · 12 cycles · 1998–2018
D+0.43University of Texas at Tyler Center for Opinion Research5 polls · 3 cycles · 2018–2022
D+0.41GfK Group21 polls · 5 cycles · 2008–2016
D+0.39MSR Group6 polls · 2 cycles · 2002–2004
D+0.39Emerson College230 polls · 11 cycles · 2013–2025
D+0.37West Chester University7 polls · 4 cycles · 2000–2006
D+0.36KRC Research11 polls · 3 cycles · 1998–2002
D+0.34Leger11 polls · 2 cycles · 2016–2020
D+0.32Market Research Institute Inc.11 polls · 3 cycles · 1998–2004
D+0.31St. Pete Polls27 polls · 7 cycles · 2012–2025
D+0.30Big Village75 polls · 8 cycles · 2006–2024
D+0.29Southeastern Louisiana University Social Science Research Center8 polls · 6 cycles · 2000–2008
D+0.29Roanoke College Institute for Policy and Opinion Research18 polls · 13 cycles · 2001–2025
D+0.28Keating Research5 polls · 3 cycles · 2012–2016
D+0.27University of Nevada, Las Vegas Lee Business School5 polls · 1 cycle · 2020
D+0.24EPIC-MRA49 polls · 13 cycles · 2000–2024
D+0.23The Tyson Group12 polls · 4 cycles · 2004–2016
D+0.23Data Orbital17 polls · 5 cycles · 2016–2024
D+0.22Digital Research19 polls · 4 cycles · 2006–2012
D+0.22Maine People's Resource Center12 polls · 3 cycles · 2012–2016
D+0.21Howey Politics/DePauw University6 polls · 2 cycles · 2008–2012
D+0.19Southern Media & Opinion Research7 polls · 4 cycles · 1999–2016
D+0.18University of Washington Center for Survey Research9 polls · 4 cycles · 2006–2012
D+0.12American Research Group86 polls · 10 cycles · 2000–2020
D+0.10InsiderAdvantage114 polls · 14 cycles · 2004–2025
D+0.09OnPoint6 polls · 1 cycle · 2006
D+0.08AtlasIntel57 polls · 4 cycles · 2020–2025
D+0.04SurveyUSA698 polls · 22 cycles · 1998–2024
D+0.01St. Norbert College Strategic Research Institute11 polls · 7 cycles · 1998–2014
R+0.02Drake Research & Strategy, Inc.8 polls · 2 cycles · 1998–2002
R+0.03Google Consumer Surveys24 polls · 2 cycles · 2012–2016
R+0.13TIPP Insights45 polls · 8 cycles · 2000–2024
R+0.17DHM Research12 polls · 8 cycles · 2000–2016
R+0.19Siena College57 polls · 13 cycles · 2002–2022
R+0.22SoCal Strategies9 polls · 2 cycles · 2024–2025
R+0.22Riley Research Associates7 polls · 3 cycles · 2002–2008
R+0.23Voter/Consumer Research8 polls · 5 cycles · 2000–2014
R+0.23Ethridge & Associates LLC6 polls · 2 cycles · 2000–2002
R+0.24Cherry Communications5 polls · 3 cycles · 2014–2022
R+0.27RKM Research and Communications Inc.21 polls · 5 cycles · 1998–2016
R+0.31Muhlenberg College33 polls · 10 cycles · 2004–2022
R+0.32National Journal12 polls · 1 cycle · 2008
R+0.32RRH Elections14 polls · 8 cycles · 2013–2022
R+0.39Los Angeles Times23 polls · 7 cycles · 1998–2008
R+0.40CVOTER6 polls · 2 cycles · 2012–2016
R+0.44Fabrizio, Lee & Associates11 polls · 5 cycles · 2008–2022
R+0.45Fairleigh Dickinson University21 polls · 12 cycles · 2001–2025
R+0.45University of Connecticut11 polls · 4 cycles · 2002–2008
R+0.47Mason-Dixon Polling & Strategy389 polls · 19 cycles · 1998–2020
R+0.56National Research12 polls · 5 cycles · 2008–2020
R+0.61Scripps Howard5 polls · 2 cycles · 2000–2002
R+0.63Opinion Dynamics28 polls · 7 cycles · 1998–2010
R+0.64Western New England University Polling Institute10 polls · 6 cycles · 2010–2018
R+0.64Zogby Analytics395 polls · 13 cycles · 1998–2014
R+0.67Louisville Courier-Journal10 polls · 7 cycles · 1998–2007
R+0.69OH Predictive Insights10 polls · 3 cycles · 2018–2022
R+0.69Brown University A. Alfred Taubman Center for American Politics and Policy8 polls · 3 cycles · 2000–2014
R+0.70Temple University Institute for Survey Research5 polls · 3 cycles · 2004–2008
R+0.72Virginia Commonwealth University L. Douglas Wilder School of Government and Public Affairs10 polls · 6 cycles · 2000–2025
R+0.73Research & Polling Inc.43 polls · 13 cycles · 1998–2022
R+0.75Ward Research15 polls · 7 cycles · 1998–2014
R+0.77Echelon Insights15 polls · 5 cycles · 2020–2025
R+0.79Market Research Insight27 polls · 5 cycles · 2003–2019
R+0.81Datamar Analytics5 polls · 2 cycles · 2006–2008
R+0.82Øptimus Analytics14 polls · 4 cycles · 2014–2020
R+0.82Magellan Strategies11 polls · 6 cycles · 2000–2018
R+0.84Saint Anselm College Survey Center9 polls · 2 cycles · 2020–2022
R+0.90Financial Dynamics15 polls · 2 cycles · 2006–2008
R+0.91Patriot Polling16 polls · 2 cycles · 2022–2024
R+0.91Gallup69 polls · 10 cycles · 1998–2018
R+0.93Fleming & Associates16 polls · 7 cycles · 1998–2018
R+1.05OpinionWorks7 polls · 3 cycles · 2010–2022
R+1.05Potomac Incorporated6 polls · 3 cycles · 1998–2006
R+1.05Hill Research Consultants5 polls · 4 cycles · 1998–2008
R+1.09WPA Intelligence16 polls · 7 cycles · 1998–2022
R+1.09JMC Analytics13 polls · 7 cycles · 2010–2020
R+1.10Harris Insights & Analytics182 polls · 8 cycles · 1998–2020
R+1.11MassINC Polling Group14 polls · 7 cycles · 2010–2020
R+1.18North Star Opinion Research10 polls · 6 cycles · 1998–2024
R+1.19Gonzales Research & Marketing Strategies Inc.9 polls · 5 cycles · 2000–2020
R+1.20Lake Research Partners/The Tarrance Group33 polls · 5 cycles · 2000–2012
R+1.22University of South Alabama Polling Group9 polls · 5 cycles · 1998–2010
R+1.26We Ask America37 polls · 4 cycles · 2010–2019
R+1.27Phillips Academy7 polls · 1 cycle · 2022
R+1.30Ciruli Associates20 polls · 6 cycles · 1998–2016
R+1.37Richard Day Research11 polls · 5 cycles · 1998–2006
R+1.39American Viewpoint8 polls · 4 cycles · 2000–2018
R+1.42Greenberg Quinlan Rosner/American Viewpoint6 polls · 4 cycles · 2010–2016
R+1.42Tarrance Group27 polls · 10 cycles · 1998–2020
R+1.44Rasmussen Reports639 polls · 18 cycles · 2000–2024
R+1.45Field Research Corp. (Field Poll)18 polls · 10 cycles · 1998–2014
R+1.47Dixie Strategies8 polls · 2 cycles · 2016–2018
R+1.61JMC Analytics/Bold Blue Campaigns5 polls · 1 cycle · 2018
R+1.63Wick16 polls · 3 cycles · 2017–2022
R+1.63Angus Reid Global31 polls · 4 cycles · 2010–2020
R+1.67Public Opinion Strategies78 polls · 13 cycles · 1998–2022
R+1.75The Polling Company Inc.7 polls · 4 cycles · 2012–2017
R+1.78New England College Polling Center19 polls · 2 cycles · 2012–2014
R+1.92Public Policy Institute of California12 polls · 10 cycles · 2004–2022
R+1.93Blum & Weprin Associates17 polls · 4 cycles · 1998–2010
R+2.01OnMessage Inc.18 polls · 7 cycles · 2003–2024
R+2.08Strategic Vision LLC110 polls · 4 cycles · 2004–2008
R+2.09Kimball Political Consulting6 polls · 1 cycle · 2012
R+2.10KAConsulting12 polls · 3 cycles · 2021–2025
R+2.25University of Cincinnati (Ohio Poll)30 polls · 8 cycles · 1998–2012
R+2.29Quantus Insights8 polls · 2 cycles · 2024–2025
R+2.32Moore Information Group18 polls · 10 cycles · 1998–2022
R+2.36Trafalgar Group113 polls · 9 cycles · 2016–2025
R+2.44McLaughlin & Associates28 polls · 11 cycles · 2000–2022
R+2.53Market Shares Corp.22 polls · 8 cycles · 1998–2012
R+2.65Carroll Strategies5 polls · 1 cycle · 2018
R+2.91Millersville University Center for Politics and Public Affairs5 polls · 3 cycles · 1998–2002
R+3.05Clout Research15 polls · 5 cycles · 2010–2017
R+3.17co/efficient23 polls · 5 cycles · 2019–2025
R+3.56ccAdvertising33 polls · 3 cycles · 2010–2014
R+4.07TCJ Research124 polls · 2 cycles · 2010–2012
R+5.09MRG Research24 polls · 3 cycles · 2010–2014
R+5.31
Method · Historical general-election polls matched to certified results; minimum 5.
Definitions · bias_D is poll D-R margin minus actual D-R margin; positive overstates Democrats.
Poll data via VoteHub, used under CC BY 4.0. Poll data from The New York Times, used under CC BY 4.0.