Will South Dakota be the closest Senate race in 2026?

The 2026 midterm elections are scheduled to be held on November 3, 2026. This market will resolve according to the US Senate race which has the smallest margin of victory. For the purpose of this market, the “margin of victory” is defined as the absolute difference between the percentages of valid votes received by the first- and second-place candidates. Percentages of the valid votes received by each candidate will be determined by dividing the total number of valid votes each of the top two candidates receives by the sum of all valid votes cast in the election. For elections that include runoffs, ranked-choice, or other multi-round elections, the relevant margin of victory will be that of the round in which the winner is determined. If two state margins of victory are identical, this market will resolve to the tied state whose name comes first alphabetically. This market will consider all regular and special Senate elections that determine representation in the upcoming 120th Congress and are scheduled to take place in November 2026 as of October 31, 2026. The resolution source for this market will be a compilation of all of the relevant state election authorities responsible for certifying statewide elections, however, a consensus of credible reporting may also be used.

Polymarket's original rules apply.