**The South Dakota U.S. Senate race between incumbent Republican Mike Rounds and independent challenger Brian Bengs remains low-visibility in a solidly Republican state, producing trader consensus around 350,000–400,000 total votes cast.** Recent polls show Rounds holding modest leads or ties depending on the survey, yet most forecasters rate the contest Safe or Solid Republican, limiting broad mobilization. The Democratic nominee’s withdrawal left a two-candidate general election on November 3, with absentee voting underway since September 18 and registration closing October 19. Historical patterns in low-turnout midterms, combined with the absence of high-salience national issues or intense campaign spending, anchor expectations near prior Senate election levels. Modest separation between the leading 375K–400K and 350K–375K bins reflects uncertainty over whether the independent bid or any late ground-game efforts will lift participation above baseline.