U.S. Senate

Counties

Every reporting unit in the race. Sort any column. The votes above are this table added up.

Model

1. Raw data

   2024 presidential baseline

   National R−D 1.5

   County presidential file. Not the 2026 result.

2. Raw data

   Generic ballot

   D 50.8 R 42.6 R−D -8.2

   National Wikipedia aggregate, October 5, 2026. State generic ballots, where a public poll exists, replace a uniform national swing: ME, MI, NH, NY, OH. A state with no generic-ballot poll keeps the national number and is not assigned a neighbor's.

3. Raw data

   Party identification

   Pew D+5 and Gallup D+10, blend R−D -7.3

   Pew NPORS 2026, identifiers plus leaners: Republican 43, Democratic 48. Gallup party identification plus leaners, first two quarters of 2026: Democratic 49, Republican 39. Pew is 55% of this blend and Gallup is 45%.

4. Model input

   National block

   R−D -7.8

   60% generic ballot and 40% party identification. The swing versus the 2024 presidential margin is what gets transmitted.

5. Model input

   Swing transmitted

   1.30 × -9.3 = -12.1

   Only the share of the national swing this state took in the last midterm is transmitted. Elasticity is shrunk halfway toward 1.

6. Raw data

   2026 early vote

   21,696 reported cast

   21,696 ballots reported cast as of 10/7/2026: 19,780 mail returned and 1,916 in person. Day-1 early vote is a signal, not a statewide margin. Mail is a count of returns, not the 2024 mail share. Applications and ballots that were only sent are not in this count. A day-1 pace gap is not a statewide margin.

7. Model input

   History block

   R−D 5.8

   The 2024 Senate opponent was an independent, and so is the opponent on this ballot. That margin is Republican minus the independent, not Republican minus a Democrat who was not on the ballot. Races against a Democrat in other years are not the prior. The county-weighted 2024 margin versus that independent is R−D 5.8.

8. Model input

   Electorate block

   R−D -0.4

   History reweighted by usual midterm turnout, plus half of the transmitted swing. Rural and presidential-only counties still move farther when the result is spread back to counties. The 2026 early-vote count is not inside this margin.

9. Model input

   Turnout block

   R−D 2.0

   Each county is weighted by its 2018 ballots divided by its 2024 presidential ballots. Small counties shrink halfway toward the state median. 2020 mail shares are not used. 21,696 ballots reported cast as of 10/7/2026: 19,780 mail returned and 1,916 in person. Day-1 early vote is a signal, not a statewide margin. Mail is a count of returns, not the 2024 mail share.

10. Model input

    National environment

    R−D -2.8

    History plus the full transmitted swing from the 60/40 national block.

11. Model input

    State environment

    R−D -0.2

    History plus 45% of the transmitted swing.

12. Model input

    State partisan lean

    R−D 20.6

    The 2024 presidential margin of this state, or of this district for a House race. It is heavier than the old state-environment block and is not shrunk toward the polling term.

13. Model input

    Trump popularity

    R−D -4.1

    New York Times approval average, October 7, 2026: 37% approve, 60% disapprove. Net approval -23. That is not a vote share. Four-tenths of the net is a margin, then scaled by this place's partisan lean (factor 0.45), so an unpopular president costs more in a Democratic state.

14. Model input

    Candidate favorability

    R−D -2.5

    Pete Ricketts's record minus this place's partisan lean is D+14.7. Thirty-five percent of that gap, capped at 5, is the favorability term, D+2.5. The old margin is not reused.

15. Model input

    Demographics

    R−D -4.4

    County college, rural, and nonwhite shares from the 2018 election-context file change how much of the swing a county takes. No separate microdata file.

16. Model input

    Finance

    R−D 2.0

    No sourced spending edge, so the block starts on history. With a poll, it shrinks toward the polling term with the other non-poll blocks.

17. Model input

    Issues

    R−D 2.0

    No sourced issue score. Same treatment as finance.

18. Model input

    Polling

    R−D -0.5

    Individual polls -1 (80%) and the Wikipedia average 1.2 (20%). Named support R−D -0.5. Allocated support R−D -0.5. No undecided line in these polls, so named support is unchanged. Banned individual rows excluded: 0. State miss shrunk 40% toward zero: 0.00. Public pollsters: 2. Outliers: 0. Recency half-life 16 days. Sample weight n/(n+350). A registered-voter poll is 0.90. An internal poll, or a poll sponsored by one party, is weighted 0.20, and only when a public poll is also in the race. An internal-only file is dropped. A poll that names both parties is not an internal. A poll more than 8 points from the median of the others is cut in half.

19. Model input

    Candidate

    R+0.75 reaches the result

    Pete Ricketts was appointed and has not won the seat, so the incumbent term is half, 0.75. Overperformance is a separate term and is not added again here. Missing the last margin or that year's presidential margin.

20. Model input

    Halfway floor

    Not applied

    The office baseline was 5.8. The blend had not moved more than halfway toward the poll.

21. Model input

    Pooling

    60% of the way from each history block toward the polling term

    The office history and the state's partisan lean differ by more than 12 points, so the history blocks move 60% of the way to the poll. Lean, Trump popularity, and favorability are not shrunk.

22. Model input

    Prediction market

    72% win probability

    Pete Ricketts 72.0% is a win probability, not a vote share. Republican win probability 72.0 from Kalshi 72.5% Republican; Polymarket 71.5% Republican. A price of 50 is a tie. Each point above 50 is 0.35 margin points, capped at 12, so the raw margin is 7.7. That margin is shrunk 40% toward the pre-market margin 3.6, which leaves 6.1. It enters once, at 2.5%. The polling term is not nudged. The market and the polls differ by more than 15 points of win probability, so the weight is half of 5% and the interval is wider.

23. Model input

    State bend

    None

    Not applied.

24. Model input

    Weights

    polling 21.0% · history 7.6% · candidate 5.8% · electorate 4.8% · national 5.8% · stateEnv 3.8% · turnout 2.8% · demographics 2.8% · finance 2.0% · issues 2.0% · stateLean 17.3% · trump 11.5% · favorability 10.5% · market 2.5%

    History is lighter. State partisan lean, Trump popularity, and candidate favorability are their own terms. A market, when it qualifies, scales every other weight and is not taken out of polling alone.

25. County-sum margin

    3.7

    Leader over the next candidate. The opponent is not the other major party, so that party's share is not zero. Pete Ricketts leads Dan Osborn by 3.7 points.

26. 80% interval

    -4.0 to 11.2

    10th to 90th percentile of 50,000 draws. Poll, national, state, turnout, and candidate error.

27. 95% interval

    -7.9 to 15.3

    2.5th to 97.5th percentile. Senate and governor state errors in the same state share a correlation of 0.30. The band shown is the marginal interval.