The 21st CenturyElections Engine

2026 / POLLING-MISS SCENARIOS

If the polls miss, who wins?

The ten closest Senate, House and governor races by 21CEE's own margin, played out three ways: Democrats beat their polls, the polls are right, or Republicans beat their polls.

Baseline: 21CEE forecast issued November 1, 2026, 8:39 p.m. ET. Scenario sizes come from real past polling misses (below).

Democrats beat the polls+0.25pts

Average of the 2018 and 2022 midterm misses (AAPOR)

The polls are right0pts

Current 21CEE margins, as issued

Republicans beat the polls+3.47pts

Average of the 2016, 2020 and 2024 presidential-year misses (AAPOR)

HOW BIG A MISS

The sizes come from past polling misses.

Democrats beat the polls+0.25 pts

Average Democratic over-performance versus final polls in the 2018 and 2022 midterms: (−0.1 in 2018 and +0.6 in 2022) ÷ 2 = +0.25. Source: AAPOR Task Force report ↗.

The polls are right0.00 pts

The current 21CEE margins exactly as issued. Nothing is shifted.

Republicans beat the polls+3.47 pts

Average Republican over-performance versus final polls in the presidential years 2016, 2020 and 2024: (+3.1, +4.6 and +2.7) ÷ 3 = +3.47. Source: AAPOR Task Force report ↗.

Final-polls miss by year, all offices. Over-performance is the amount by which the winning side beat the final polls on the margin.
YearAAPOR task force findingUsed (pts)Cross-check
2016presidential yearpolls too Democratic by 3.1+3.1GOP over-performancepolls too Democratic by 3.0 (538)
2018midtermpolls too Democratic by 0.1−0.1Dem over-performancepolls too Republican by 0.5 (538)
2020presidential yearpolls too Democratic by 4.6+4.6GOP over-performancepolls too Democratic by 4.7 (538)
2022midtermpolls too Republican by 0.6+0.6Dem over-performancepolls too Democratic by 0.8 (538)
2024presidential yearpolls too Democratic by 2.7+2.7GOP over-performancepolls too Democratic by 2.9 (Silver Bulletin)

The Democratic size is small because the two midterm misses nearly cancelled: polls overstated Democrats by 0.1 point in 2018 and overstated Republicans by 0.6 point in 2022. Other measures of the same years agree the net is close to zero (cross-check average: −0.15 pts for Democrats; 3.53 pts for Republicans in presidential years).

THE TEN CLOSEST · SENATE

Senate: three ways it can break.

21CEE publishes a numeric margin for 12 of 35 Senate contests; the ten closest of those are shown. The other 23 keep their 21CEE calls in every scenario. A 0.25-point Democratic miss is too small to flip any senate race.

Democrats beat the polls52DEM46GOP2I52D / 46R / 2I (both caucus with D)Democrats control the Senate0 seat changes vs. 21CEE
The polls are right52DEM46GOP2I52D / 46R / 2I (both caucus with D)Democrats control the Senate0 seat changes vs. 21CEE
Republicans beat the polls46DEM52GOP2I46D / 52R / 2I (both caucus with D)Republicans control the Senate6 seat changes vs. 21CEE

THE TEN CLOSEST · HOUSE

House: three ways it can break.

21CEE publishes a numeric margin for 64 of 435 House districts; the ten closest of those are shown. The other 371 keep their 21CEE calls in every scenario. A 0.25-point Democratic miss is too small to flip any house race.

Democrats beat the polls236DEM199GOP236D / 199RDemocrats control the House0 seat changes vs. 21CEE
The polls are right236DEM199GOP236D / 199RDemocrats control the House0 seat changes vs. 21CEE
Republicans beat the polls216DEM219GOP216D / 219RRepublicans control the House20 seat changes vs. 21CEE
#1

OH-09

Ohio · District 921CEE: Even
Marcy KapturMarcy KapturDEMDerek MerrinDerek MerrinGOP
DEM beat pollsMarcy KapturMarcy KapturDEMD+0.25Holds
Polls rightMarcy KapturMarcy KapturDEMEven21CEE call
GOP beat pollsDerek MerrinDerek MerrinGOPR+3.47Flips to GOP
#3

CA-06

California · District 621CEE: D+0.20
Richard PanRichard PanDEMKevin KileyKevin KileyICaucus: None announced: says he will not caucus with Republicans if re-elected
DEM beat pollsRichard PanRichard PanDEMD+0.45Holds
Polls rightRichard PanRichard PanDEMD+0.2021CEE call
GOP beat pollsRichard PanRichard PanDEMD+0.20Holds
#5

TX-35

Texas · District 3521CEE: R+1.00
Johnny C. GarciaJohnny C. GarciaDEMCarlos De La CruzGOPPhoto not available
DEM beat pollsCarlos De La CruzGOPPhoto not availableR+0.75Holds
Polls rightCarlos De La CruzGOPPhoto not availableR+1.0021CEE call
GOP beat pollsCarlos De La CruzGOPPhoto not availableR+4.47Holds
#9

KY-06

Kentucky · District 621CEE: R+1.27
Zach DemboZach DemboDEMRalph AlvaradoRalph AlvaradoGOP
DEM beat pollsRalph AlvaradoRalph AlvaradoGOPR+1.02Holds
Polls rightRalph AlvaradoRalph AlvaradoGOPR+1.2721CEE call
GOP beat pollsRalph AlvaradoRalph AlvaradoGOPR+4.74Holds
16 more house seat changes outside these ten
  • AZ-01 goes to Jay Feely (GOP) when Republicans beat the polls
  • AZ-02 goes to Elijah Crane (GOP) when Republicans beat the polls
  • CA-13 goes to Kevin Lincoln (GOP) when Republicans beat the polls
  • FL-25 goes to Scott Singer (GOP) when Republicans beat the polls
  • IA-01 goes to Mariannette Miller-Meeks (GOP) when Republicans beat the polls
  • IA-02 goes to Joe Mitchell (GOP) when Republicans beat the polls
  • IA-03 goes to Zach Nunn (GOP) when Republicans beat the polls
  • MN-01 goes to Brad Finstad (GOP) when Republicans beat the polls
  • NM-02 goes to Gregory G Cunningham (GOP) when Republicans beat the polls
  • NY-04 goes to Jeanine C. Driscoll (GOP) when Republicans beat the polls
  • NY-17 goes to Mike Lawler (GOP) when Republicans beat the polls
  • OH-07 goes to Max Miller (GOP) when Republicans beat the polls
  • PA-01 goes to Brian Fitzpatrick (GOP) when Republicans beat the polls
  • TX-15 goes to Monica De La Cruz (GOP) when Republicans beat the polls
  • VA-02 goes to Jen Kiggans (GOP) when Republicans beat the polls
  • WI-03 goes to Derrick Van Orden (GOP) when Republicans beat the polls

THE TEN CLOSEST · GOVERNOR

Governor: three ways it can break.

21CEE publishes a numeric margin for 12 of 36 governor races; the ten closest of those are shown. The other 24 keep their 21CEE calls in every scenario. A 0.25-point Democratic miss is too small to flip any governor race.

Democrats beat the polls27DEM23GOP27D / 23RDemocrats hold more governorships0 seat changes vs. 21CEE
The polls are right27DEM23GOP27D / 23RDemocrats hold more governorships0 seat changes vs. 21CEE
Republicans beat the polls25DEM25GOP25D / 25RGovernorships split evenly2 seat changes vs. 21CEE
#4

Texas Governor

21CEE: R+2.48
Gina HinojosaDEMPhoto not availableGreg AbbottGreg AbbottGOP
DEM beat pollsGreg AbbottGreg AbbottGOPR+2.23Holds
Polls rightGreg AbbottGreg AbbottGOPR+2.4821CEE call
GOP beat pollsGreg AbbottGreg AbbottGOPR+5.95Holds
#6

Florida Governor

21CEE: R+4.25
David JollyDEMPhoto not availableByron DonaldsByron DonaldsGOP
DEM beat pollsByron DonaldsByron DonaldsGOPR+4.00Holds
Polls rightByron DonaldsByron DonaldsGOPR+4.2521CEE call
GOP beat pollsByron DonaldsByron DonaldsGOPR+7.72Holds

METHODS & SOURCES

How these scenarios are built.

  1. Baselines are 21CEE only. Every race, candidate and margin comes from the 21CEE forecast issued November 1, 2026, 8:39 p.m. ET (snapshot 6c60a152e3df). Nothing from another forecaster is used.
  2. Ten closest. Within each chamber, races are ranked by the size of the current 21CEE margin. Only races with a published numeric margin can be ranked or shifted; the rest keep their 21CEE calls.
  3. One uniform shift. In a Democrats-beat-the-polls scenario every ranked race moves 0.25 points toward the Democratic candidate. In a Republicans-beat-the-polls scenario every ranked race moves 3.47 points toward the Republican candidate. If a race has no candidate from that party (an independent against one major party), it does not move.
  4. Totals and control. Chamber totals start from the 21CEE totals and change only for races whose winner changes. Senate control needs 51 seats counting the two independents who caucus with the Democrats; 50-50 goes to the vice president's party. House control needs 218.
  5. Illustrations, not probabilities. These show what happens if every race misses by the same amount in the same direction. Real misses vary by race and are rarely uniform. The sizes are averages of past national misses, not a forecast of this year's error.

Sources

Independent candidates show their stated caucus plans. Photographs and credits follow the References & credits page.