Closest Senate race in 2026?: Will South Dakota have the smallest margin of victory in 2026 United States Senate elections?

If South Dakota has the smallest margin of victory among all elections in the 2026 United States Senate elections as of Jan 3, 2027, then the market resolves to Yes. Margin of victory is calculated as the absolute percentage point difference between first and second place finishers. For two-candidate races, this is winner's percentage minus runner-up's percentage. For multi-candidate races, only the gap between first and second counts. For ranked choice/instant runoff elections, the margin from the final round is used. If official results aren't available by the deadline but at least 95% of expected vote is counted, preliminary results are used. In case of identical margins (tied to the hundredth of a percentage point), tied options split the payout equally. Postponed elections or those without sufficient results by the deadline resolve to No.