ID-02 · U.S. House
Open this race on The Map ↗Mike Simpson is almost certain to hold Idaho’s 2nd congressional district. Predicted margin: R+21.0.
high / low: vote share (%) in the middle 80 in 100 simulations · * incumbent
Forecast history
Latest reading · Oct 23 · first published Sep 9 · 80% range · margin points R+28.1 to R+13.9. Methodology
Hover the line, tap it, or use the arrow keys to read the margin on a day.
About this series
Reconstructed with the current model Aug 1 – Sep 8 and Sep 16 – Sep 18; published readings Sep 9 – Oct 23. Each reconstructed day is the current model on that day’s own inputs, not a forecast published then. Corrections are dated in the changelog.
Faded: CTMM 2.2 reconstructed history: computed after the fact with each date's available polls and environment, without expert ratings; not an issued forecast. Issued forecasts begin at the launch marker.
CTMM 2.2 readings for 2026-09-16, 2026-09-17, 2026-09-18 were computed after the fact with each day's available inputs: no edition was issued on those days. Not an issued forecast.
Data table
| Date | Margin | Chance | 80% range | Reading |
|---|---|---|---|---|
| Oct 23 | R+21.0 | R win 99.0% | R+28.1 to R+13.9 | Published forecast |
| Oct 22 | R+21.0 | R win 99.0% | R+28.1 to R+13.9 | Published forecast |
| Oct 21 | R+21.0 | R win 99.0% | R+28.1 to R+13.9 | Published forecast |
| Oct 20 | R+21.0 | R win 99.0% | R+28.1 to R+13.9 | Published forecast |
| Oct 19 | R+21.1 | R win 99.0% | R+28.2 to R+14.0 | Published forecast |
| Oct 18 | R+21.1 | R win 99.0% | R+28.2 to R+14.0 | Published forecast |
| Oct 17 | R+21.1 | R win 99.0% | R+28.2 to R+13.9 | Published forecast |
| Oct 16 | R+21.1 | R win 99.0% | R+28.2 to R+14.0 | Published forecast |
| Oct 15 | R+21.2 | R win 99.0% | R+28.3 to R+14.0 | Published forecast |
| Oct 14 | R+21.2 | R win 99.0% | R+28.3 to R+14.1 | Published forecast |
| Oct 13 | R+21.2 | R win 99.0% | R+28.3 to R+14.1 | Published forecast |
| Oct 12 | R+21.2 | R win 99.0% | R+28.3 to R+14.1 | Published forecast |
| Oct 11 | R+21.2 | R win 99.0% | R+28.3 to R+14.0 | Published forecast |
| Oct 10 | R+21.2 | R win 99.0% | R+28.3 to R+14.0 | Published forecast |
| Oct 9 | R+21.2 | R win 99.0% | R+28.4 to R+14.0 | Published forecast |
| Oct 8 | R+21.2 | R win 99.0% | R+28.4 to R+14.1 | Published forecast |
| Oct 7 | R+21.2 | R win 99.0% | R+28.4 to R+14.1 | Published forecast |
| Oct 6 | R+21.3 | R win 99.0% | R+28.5 to R+14.2 | Published forecast |
| Oct 5 | R+21.3 | R win 99.0% | R+28.5 to R+14.2 | Published forecast |
| Oct 4 | R+21.3 | R win 99.0% | R+28.5 to R+14.1 | Published forecast |
| Oct 3 | R+21.3 | R win 99.0% | R+28.5 to R+14.2 | Published forecast |
| Oct 2 | R+21.4 | R win 99.0% | R+28.6 to R+14.2 | Published forecast |
| Oct 1 | R+21.4 | R win 99.0% | R+28.5 to R+14.2 | Published forecast |
| Sep 30 | R+21.3 | R win 99.0% | R+28.5 to R+14.1 | Published forecast |
| Sep 29 | R+21.4 | R win 99.0% | R+28.6 to R+14.2 | Published forecast |
| Sep 28 | R+21.4 | R win 99.0% | R+28.6 to R+14.2 | Published forecast |
| Sep 27 | R+21.4 | R win 99.0% | R+28.6 to R+14.2 | Published forecast |
| Sep 26 | R+21.4 | R win 99.0% | R+28.6 to R+14.2 | Published forecast |
| Sep 25 | R+21.4 | R win 99.0% | R+28.6 to R+14.2 | Published forecast |
| Sep 24 | R+21.4 | R win 99.0% | R+28.7 to R+14.2 | Published forecast |
| Sep 23 | R+21.5 | R win 99.0% | R+28.7 to R+14.2 | Published forecast |
| Sep 22 | R+21.5 | R win 99.0% | R+28.8 to R+14.3 | Published forecast |
| Sep 21 | R+21.5 | R win 99.0% | R+28.8 to R+14.3 | Published forecast |
| Sep 20 | R+21.5 | R win 99.0% | R+28.8 to R+14.3 | Published forecast |
| Sep 19 | R+21.5 | R win 99.0% | R+28.8 to R+14.3 | Published forecast |
| Sep 18 | R+21.4 | R win 99.0% | R+28.7 to R+14.2 | Reconstructed with the stated inputs |
| Sep 17 | R+21.5 | R win 99.0% | R+28.7 to R+14.2 | Reconstructed with the stated inputs |
| Sep 16 | R+21.5 | R win 99.0% | R+28.8 to R+14.2 | Reconstructed with the stated inputs |
| Sep 15 | R+21.7 | R win 99.0% | R+28.9 to R+14.4 | Published forecast |
| Sep 14 | R+21.6 | R win 99.0% | R+28.9 to R+14.3 | Published forecast |
| Sep 13 | R+21.6 | R win 99.0% | R+28.9 to R+14.3 | Published forecast |
| Sep 12 | R+21.6 | R win 99.0% | R+28.9 to R+14.3 | Published forecast |
| Sep 11 | R+21.7 | R win 99.0% | R+29.0 to R+14.4 | Published forecast |
| Sep 10 | R+21.7 | R win 99.0% | R+29.0 to R+14.4 | Published forecast |
| Sep 9 | R+21.9 | R win 99.0% | R+29.2 to R+14.6 | Published forecast |
| Sep 8 | R+21.8 | R win 99.1% | R+29.1 to R+14.5 | Reconstructed with the stated inputs |
| Sep 7 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Sep 6 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Sep 5 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Sep 4 | R+21.9 | R win 99.1% | R+29.2 to R+14.6 | Reconstructed with the stated inputs |
| Sep 3 | R+21.9 | R win 99.1% | R+29.2 to R+14.6 | Reconstructed with the stated inputs |
| Sep 2 | R+21.9 | R win 99.1% | R+29.3 to R+14.6 | Reconstructed with the stated inputs |
| Sep 1 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Aug 31 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Aug 30 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Aug 29 | R+21.9 | R win 99.1% | R+29.2 to R+14.5 | Reconstructed with the stated inputs |
| Aug 28 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 27 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 26 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 25 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 24 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 23 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 22 | R+21.9 | R win 99.1% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 21 | R+21.9 | R win 98.9% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 20 | R+21.9 | R win 98.9% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 19 | R+21.9 | R win 98.9% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 18 | R+21.9 | R win 98.9% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 17 | R+21.9 | R win 98.9% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 16 | R+21.9 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 15 | R+21.9 | R win 98.9% | R+29.3 to R+14.5 | Reconstructed with the stated inputs |
| Aug 14 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 13 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 12 | R+21.9 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 11 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 10 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 9 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 8 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 7 | R+22.0 | R win 98.9% | R+29.4 to R+14.5 | Reconstructed with the stated inputs |
| Aug 6 | R+22.0 | R win 98.9% | R+29.5 to R+14.6 | Reconstructed with the stated inputs |
| Aug 5 | R+22.0 | R win 98.9% | R+29.5 to R+14.6 | Reconstructed with the stated inputs |
| Aug 4 | R+22.0 | R win 98.9% | R+29.5 to R+14.5 | Reconstructed with the stated inputs |
| Aug 3 | R+22.0 | R win 98.9% | R+29.6 to R+14.5 | Reconstructed with the stated inputs |
| Aug 2 | R+22.1 | R win 98.9% | R+29.6 to R+14.6 | Reconstructed with the stated inputs |
| Aug 1 | R+22.1 | R win 98.9% | R+29.6 to R+14.5 | Reconstructed with the stated inputs |
How the margin was built
Follow each contribution to the margin. Wider ribbons mean more percentage points. Tap an input for its calculation and source.
The signed totals combine at the forecast. Displayed values are rounded.
All calculations & sources
This district's measured terrain −27.752 points
Call the Map's partisan lean on the CURRENT district lines, before any current-cycle evidence. Every pull below is measured from here — not from EVEN.
- Call the Map partisan lean, district geography bound to this forecast edition.
- Prior source: observed_unchanged_lines.
Fitted model, above the terrain shown +3.410 points
What the fitted model adds on top of the starting terrain above — incumbency, past results, campaign finance and the other fitted terms — measured from that terrain rather than from EVEN. It is a comparison with the starting point already shown, not a separate input. The source detail lists the variables the fit uses.
- Fitted baseline -24.342 minus starting point -27.752 = 3.410 points.
- One fitted structural total; this edition does not split it into partisan lean and incumbency.
- Fundamentals: −24.3 — the district's structural lean before this year's polling, money and candidate quality are added.
- This edition publishes that as one fitted total. It does not break it into a partisan-lean and an incumbency term, so this page does not invent that split.
- fundamentals core = 25-term dynamic formula (mass fit over the master feature matrix, held-out-cycle validated; see matrix/feature_dictionary.md + mass_fit_report.json)
- 40-term formula, held-out validated.
National environment +2.013 points
The contribution to this race’s margin, not the national polling margin itself. The race’s loading, reference level and polling blend determine how much of the national climate reaches its final forecast.
- Three-source blend, updated 2026-10-14: 53% generic-ballot aggregates (D+7.7) · 28% special-election overperformance (D+9.0 across 46 specials) · 20% approval-implied (D+9.1 from net approval -24.3).
- Latest polls — generic ballot 2026-10-14 (10 days old), approval 2026-10-14 (10 days old).
- Generic-ballot average D+7.7 · support factor 0.87 (the share of that channel's capacity the admitted polls carry) — separate inputs; their product is a capacity diagnostic, not a margin.
- Weights are the 55/25/20 capacities scaled by each channel's evidence and renormalized, so thin polling widens the interval instead of pulling the center toward zero — 12% of the weight is carried that way.
- Blended national environment: D+8.3.
- Applied at full strength to this chamber's races.
- This step’s recorded contribution to the margin is +2.0.
- Blended national environment: D+8.3 (updated 2026-10-14).
- Effective poll weight 88%; fundamentals share 12%, carried by the interval (×1.06) rather than by the center.
- The support factor is the share of the generic-ballot capacity the admitted polls carry; average × support is a capacity diagnostic, not a margin, and is not what the row above multiplies.
- Applied at full strength to this chamber: +2.0 of this margin.
Votes for other candidates +1.340 points
Every step above is measured between the two major-party candidates alone, as if nobody else were on the ballot. The forecast sets 6.0% of the vote aside for other candidates and write-ins, so as a share of every vote cast the gap between the two is smaller by that much. This step is exactly that: the two-party margin times the share going to other candidates. It is the same arithmetic that turns the two-party margin into the two shares printed at the top of the page.
The components this edition publishes for this race, in points. “Other factors” closes the sum to the two-party structural lean exactly. The margin the page prints is a share of every vote cast, so the “Votes for other candidates” row carries the exact difference between the two-party lean and that margin; with it, the walk sums to the printed margin exactly.
| Named factor | Contribution |
|---|---|
| FundamentalsThe admitted fitted baseline. Its surviving variables differ by office; the source detail above identifies those used for this race. | −24.34 |
| National environmentThe national environment’s contribution to the prior. Polling can attenuate its influence; this value is not the national polling margin. | +2.01 |
| Other factors | 0.00 |
Where the votes are
The map of this race loads here.
Recent elections
| Election | Result | Votes cast |
|---|---|---|
| 2024 · U.S. House ↗ | R+28.9 | 428,514 |
| 2022 · U.S. House ↗ | R+27.2 | 271,186 |
| 2020 · U.S. House ↗ | R+32.3 | 391,333 |
| 2018 · U.S. House ↗ | R+21.3 | 280,655 |
Historical district boundaries may differ. Margins are the Democrat’s share of all votes cast minus the Republican’s. Nonstandard ballots are labeled separately.
The money
Mike Simpson ↗
R$1.1Mraised
$429K cash on handFiling through 06/30/2026
Elinor Gilbreath ↗
D$107Kraised
$71K cash on handFiling through 06/30/2026
Bar length compares reported receipts in this race; the tick marks cash on hand. A missing filing stays blank rather than becoming $0.
One more fundraising reportCall the Map · $315
The candidates are comfortably out-fundraising the website covering them. A little rude, perhaps, but statistically unsurprising.
- Received so far
- $315
- Measured compute
- $26,188.58
Ko-fi and Buy Me a Coffee supports are counted as each one arrives. Measured compute prices model runs at standard published API rates; it is not what I paid. Hosting, data and subscriptions, the domain and my own time are not counted. Donations buy gratitude, never a forecast adjustment.
Supporters are listed by first name and last initial; a username alone is shortened to its first eight characters. Want your full name shown? Say so in your message. Give privately, or leave the name blank, and you are listed as Anonymous, with the platform and date. Supporters who give a name may also be thanked by name in the newsletter.
Thank you to Tom H., ColoradoFlyer, Chris, EW, gbaileym…, True Independent, MT V., JBL, Erin G., Caroline M., Melanie, MKV and 6 more.
No outside spending matched: Mike Simpson, Elinor Gilbreath.
FEC filings · through 06/30/2026 · Definitions & method
Race context
- 2024 presidential vote here
- 422,563
- 2024 presidential margin
- R+27.6between the two parties
Population profile Select a measure for its source and denominator
U.S. Census Bureau, 2022 American Community Survey 5-year estimates ↗
Forecast as of October 23, 2026: Call the Map currently has Mike Simpson ahead of Elinor Gilbreath by R+21.0, with a 99 in 100 chance to win. The seat is currently held by a Republican. That result would keep the seat with Republicans. No current nominee-matched poll average is available, so the forecast is leaning on the non-polling evidence shown below.