Pollsters such as Nate Silver were giving gut-takes of Red over Blue, e.g.:
"Nate Silver: Here’s What My Gut Says About the Election, but Don’t Trust Anyone’s Gut, Even Mine" (Oct. 23, 2024)
<https://www.nytimes.com/2024/10/23/opinion/election-polls-re...>
I've done a somewhat half-assed take tonight of comparing actual returns to latest pre-election polling by state
Why that is, isn't clear. Political pollsters have been struggling for years with accuracy issues, particularly as landline usage falls (it's <20% in most states now), and unknown-caller blocking is more widely used (both on landlines and mobile devices).
Polling does have periodic calibration events (we call those "elections"), but whatever biases the polls seem to experience in the US, it's apparently systemically exceeding adjustment factors.
Polls / votes and deltas:
QC State EV BP RP BV RV Bd Rd
4: AL 9 36 64 32 65 -4 1
4: AK 3 45 55 0 0
4: AZ 11 49 51 49 50 0 -1
4: AR 6 36 64 34 64 -2 0
4: CA 54 63 37 60 37 -3 0
4: CO 10 56 44 55 43 -1 -1
4: CT 7 59 41 54 44 -5 3
4: DC 3 92 7 90 7 -2 0
4: DE 3 58 42 56 42 -2 0
4: FL 30 47 53 43 56 -4 3
4: GA 16 49 51 48 51 -1 0
4: HI 4 64 36 0 0
4: ID 4 33 67 33 64 0 -3
4: IL 19 57 43 52 47 -5 4
4: IN 11 41 57 39 59 -2 2
4: IA 6 46 54 42 56 -4 2
4: KS 6 42 51 41 57 -1 6
4: KY 8 36 64 34 64 -2 0
4: LA 8 40 60 38 60 -2 0
4: ME 2 54 46 0 0
4: ME-1 1 61 39 0 0
4: ME-2 1 47 53 0 0
4: MD 10 64 36 60 37 -4 1
4: MA 11 64 36 62 35 -2 -1
4: MI 15 50 49 0 0
4: MN 10 53 47 0 0
4: MS 6 40 60 37 62 -3 2
4: MO 10 43 57 42 56 -1 -1
4: MT 4 41 59 33 64 -8 5
4: NE 4 41 59 42 56 1 -3
4: NE-2 1 54 46 0 0
4: NM 5 54 46 51 47 -3 1
4: NV 6 50 50 0 0
4: NH 4 53 47 52 47 -1 0
4: NJ 14 57 43 51 46 -6 3
4: NY 28 59 41 55 44 -4 3
4: NC 16 49 51 48 51 -1 0
4: ND 3 33 67 31 67 -2 0
4: OH 17 46 54 44 55 -2 1
4: OK 7 33 67 32 66 -1 -1
4: OR 8 56 44 55 43 -1 -1
4: PA 19 50 50 0 0
4: RI 4 58 42 55 42 -3 0
4: SC 9 44 56 40 58 -4 2
4: SD 3 36 64 29 69 -7 5
4: TN 11 38 62 34 64 -4 2
4: TX 40 46 54 42 57 -4 3
4: UT 6 39 61 43 54 4 -7
4: VT 3 67 34 64 32 -3 -2
4: VA 13 53 47 51 47 -2 0
4: WA 12 59 41 58 39 -1 -2
4: WV 4 30 70 28 70 -2 0
4: WI 10 50 49 0 0
4: WY 3 73 27 70 28 -3 1
Blue votes: 43
Red votes: 43
Blue delta: -2.49
Red delta: 0.63
Key:- QC: A parsing QC value (number of raw fields)
- State: 2-char state code, dash-number indicates individual EVs for NE and ME.
- EV: Electoral votes
- BP: Blue polling
- RP: Red polling
- BV: Blue vote return
- RV: Red vote return
- Bd: Blue delta (vote - poll)
- Rd: Red delta (vote - poll)
The last two results are the cumulative average deltas. Blue consistently performed ~2.5 points below polls, red performed ~0.6 points above polls.
Data are rounded to nearest whole percent (I'd like to re-enter data to 0.1% precision and re-run, though overall effect should be similar). Deltas are computed only where voting returns are >0.
Data are hand-entered from 538 and ABC returns pages.
Blue consistently polled slightly higher than performance. Polls don't seem to include third parties (mostly Green, some state returns include RFK or others).
There are all but certainly coding/data entry errors here, though for illustration the point should hold.
With updated (and 0.1% decimal precision) election returns, Harris's polling delta falls to -2.25% (Orange is unchanged). The overall advantage of her opponent over polling data is 2.89%. Which is a lot.
Still want to get more precise polling numbers in there, but again, it's not shifting a lot. Law of Large Numbers dictates that, as multiple rounded numbers tend to even out the precision distinction.
I've just re-run my analysis with higher precision on the deltas. Harris performed worse in every single race save DC than projected. Orange performed better in a majority of races, by as much as 5+ percent.
(I still need more accurate data for polling, I'll add a comment when I've updated that.)
So basically consistent with 2016 and 2020: Most polls have a 2-5 point bias in favor of Democrats. Maybe a bit improved from previous elections.
State EV Poll (D/R) Vote (D/R) Delta (D/R) Win
AL 9 36.1 63.9 34.2 64.8 -1.9 0.9 R
AK 3 45.1 54.9 40.4 55.6 -4.7 0.7 R
AZ 11 49.0 51.0 47.2 51.9 -1.8 0.9 R
AR 6 35.7 64.3 33.6 64.2 -2.1 -0.1 R
CA 54 62.7 37.3 57.4 40.0 -5.3 2.7 D
CO 10 56.2 43.8 54.6 43.1 -1.6 -0.7 D
CT 7 58.7 41.3 54.5 43.8 -4.2 2.5 D
DC 3 92.4 7.6 92.4 6.7 0.0 -0.9 D
DE 3 58.1 41.9 56.5 42.0 -1.6 0.1 D
FL 30 47.0 53.1 43.0 56.1 -4.0 3.0 R
GA 16 49.4 50.6 48.5 50.8 -0.9 0.2 R
HI 4 63.7 36.3 62.2 36.1 -1.5 -0.2 D
ID 4 33.2 66.8 30.7 66.5 -2.5 -0.3 R
IL 19 57.4 42.6 53.3 45.3 -4.1 2.7 D
IN 11 41.4 58.6 39.2 59.1 -2.2 0.5 R
IA 6 46.4 53.7 42.3 56.3 -4.1 2.6 R
KS 6 41.9 58.1 40.8 57.4 -1.1 -0.7 R
KY 8 36.0 64.0 33.9 64.6 -2.1 0.6 R
LA 8 39.6 60.4 38.2 60.2 -1.4 -0.2 R
ME 2 54.3 45.7 53.1 44.3 -1.2 -1.4 D
ME-1 1 61.2 38.8 60.4 33.6 -0.8 -5.2 D
ME-2 1 46.9 53.1 45.0 52.9 -1.9 -0.2 R
MD 10 64.2 35.8 60.2 37.3 -4.0 1.5 D
MA 11 64.0 36.0 61.9 35.9 -2.1 -0.1 D
MI 15 50.6 49.4 48.2 49.8 -2.4 0.4 R
MN 10 52.9 47.1 51.1 46.8 -1.8 -0.3 D
MS 6 40.5 59.5 37.7 61.1 -2.8 1.6 R
MO 10 42.9 57.2 40.1 58.5 -2.8 1.3 R
MT 4 41.0 59.0 38.4 58.5 -2.6 -0.5 R
NE 4 41.3 58.7 38.5 60.2 -2.8 1.5 R
NE-1 1 41.6 58.4 42.4 56.3 0.8 -2.1 R
NE-2 1 53.5 46.5 51.2 47.5 -2.3 1.0 D
NE-3 1 22.6 77.4 22.5 76.3 -0.1 -1.1 R
NM 5 53.7 46.3 51.6 46.1 -2.1 -0.2 D
NV 6 50.0 50.0 46.8 51.5 -3.2 1.5 R
NH 4 53.0 47.0 51.0 48.0 -2.0 1.0 D
NJ 14 56.9 43.2 51.5 46.6 -5.4 3.4 D
NY 28 58.9 41.5 55.4 44.6 -3.5 3.1 D
NC 16 49.4 50.6 47.7 51.1 -1.7 0.5 R
ND 3 33.3 66.7 30.8 67.5 -2.5 0.8 R
OH 17 45.8 54.2 43.9 55.2 -1.9 1.0 R
OK 7 33.2 66.8 31.9 66.2 -1.3 -0.6 R
OR 8 56.5 43.6 54.9 42.5 -1.6 -1.1 D
PA 19 50.0 50.0 48.4 50.7 -1.6 0.7 R
RI 4 58.4 41.7 55.5 42.4 -2.9 0.7 D
SC 9 43.7 56.3 40.5 58.1 -3.2 1.8 R
SD 3 36.0 64.0 33.0 64.7 -3.0 0.7 R
TN 11 38.1 61.9 34.4 64.3 -3.7 2.4 R
TX 40 46.3 53.7 42.4 56.3 -3.9 2.6 R
UT 6 38.9 61.1 38.9 58.9 0.0 -2.2 R
VT 3 66.5 33.5 64.3 32.6 -2.2 -0.9 D
VA 13 53.4 46.6 51.8 46.6 -1.6 0.0 D
WA 12 58.9 41.1 58.6 39.1 -0.3 -2.0 D
WV 4 29.8 70.2 27.9 70.2 -1.9 0.0 R
WI 10 50.6 49.5 48.8 49.7 -1.8 0.2 R
WY 3 27.4 72.6 26.1 72.3 -1.3 -0.3 R
Blue votes: 56
Red votes: 56
Blue delta: -2.26
Red delta: 0.42
Observations:- Harris did more poorly than forecast in all but three races: DC, UT, and NE-1.
- Her opponent did better than forecast in 32 races.
- Many of Harris's bigger under-performances were in races she won, notably CA. FL and TX are losses with far worse-than-polled returns.
Net average polling bias is 2.68 points favouring the GOP across 56 contests.