Kansas Senate

The adjustment starts from the polling read above and adds up to three terms. Recent polling error: a lean toward Democrats, sized for each state. Spending: outside money in the two weeks to 2026-11-02, compared with what a race this close usually draws, read against the state’s 2024 presidential result. Early vote: where the state reports early voters’ party registration, how far its shift since 2022 runs ahead of or behind the other states’.

Spending and the state’s polling record are two witnesses to where this year’s miss lands. Each is weighted by how reliable it has been in 44 Senate races from 2020 and 2022: the state record counts 56% and spending 44%, at 1.26 points per standard deviation of extra money. Spending is measured against other races this year, so it places the miss; it does not size the national lean. Early vote counts 0.38 points per point of relative shift, fit on 22 states in the 2018 and 2022 midterms, each against the midterm before; held out a year at a time, it cut the average miss from 4.0 to 3.8 points. The national polling-error lean is 1.9 points, give or take 2.8: in regular elections in every off-year since 1999 (specials and Louisiana primaries left out), about a quarter of that year’s polling miss repeated in the next year’s elections, and the 2025 miss was 7.3 points toward Democrats. The margin of error includes both the uncertainty in that carryover share and how far a year has strayed from it in the past, along with the race-by-race error of a final polling average, about 4 points. That history is thin: in a replay of the lean on past races, results landed inside a band built this way 62% of the time, short of the 68% a well-sized band would cover, so treat the ± as a floor. Each state then moves by 0.69 times its own average miss against the national miss over the last 12 years; here that is +0.3 points across 5 election cycles.

2024 presidential result

R +16.1

Outside money, two weeks

$34.3M D-side · $6.1M R-side

Outside money against a race this close

+0.57 SD

Early vote vs 2022, by registration

-13.3 D · -12.2 vs other states

Margin of error, one standard deviation

± 5.4 points: 3.5 from our adjustments, 4.1 from this race’s own polling error

Outside spending is FEC independent expenditures only; campaigns’ own ad budgets and reservations are not included. Polls missed Democrats last fall by more than in any off-year on record, and kept missing them this spring. The undertow bets part of that carries into November. Outside spending, read as a sign of where campaigns' internal polls stand, is weighed against each state's own polling record to place the miss race by race, and early voting adds where it can be measured like for like. Frozen on November 2 and graded against certified results beside the polls.