Race2026 cycleElection day 3 Nov 2026Updated

Cite this page

DonorAlpha, “South Dakota Senate general 2026”, https://donoralpha.com/races/south-dakota-senate-general-2026?e=c2026, updated .

South Dakota Senate general 2026

Prediction market7 Oct 2026

Mike Rounds 92.5% · prediction market price

No. 45 of 68 Senate races in the 2026 cycle

The short version

In the 2026 South Dakota Senate general election, 2 outside groups spent $780K: $550K opposing Brian Bengs (I) and $230K supporting Mike Rounds (R).

$780K

outside money

opposing Brian Bengs (I)
$550K
supporting Mike Rounds (R)
$230K

Result not in yet

Election day is 3 Nov 2026.

  • Brian Bengs

    Independent

    Waiting for the count

  • Mike Rounds

    Republican

    Waiting for the count

Outside money supporting and opposing each candidate

Both sides on one scale
← OpposingSupporting →
  • Brian Bengs Independent

    $550K

    $550K opposing Brian Bengs

  • Mike Rounds Republican

    $230K

    $230K supporting Mike Rounds

This seat, every election

South Dakota Senate

$1.3M

outside money in the 2026 cycle

The long version

The candidates

What each candidate’s own campaign raised, beside what outside groups spent supporting and opposing them.

  • Brian Bengs

    Independent

    Own campaign raised
    $782K
    Outside money opposing
    $550K
    Bengs for South Dakota
  • Mike Rounds

    Republican

    Own campaign raised
    $3.2M
    Outside money supporting
    $230K
    Rounds for Senate
  • Campaign money to 30 Jun 2026

Week by week

Outside money each week, supporting and opposing the candidates, all candidates combined.

Week of 28 Sep 2026

Supporting $230KOpposing $136K

Supporting candidatesOpposing candidates

The groups on each side

The biggest outside groups in this race, by what they spent supporting or opposing each candidate.

Spent supporting a candidate

  1. American Missionsupporting Mike Rounds$230K

Spent opposing a candidate

  1. South Dakota Conservative PACopposing Brian Bengs$550K

Who’s connected to whom

The groups that spent supporting or opposing the candidates.

Their biggest giversGroups that spentCandidatesSouth Dakota Conservative PAC spent $550K opposing Brian Bengs · $550KAmerican Mission spent $230K supporting Mike Rounds · $230KCondorcet gave $100K to South Dakota Conservative PAC · $100KCustom Management Services gave $50,000 to South Dakota Conservative PAC · $50,000Lonsdale Enterprises (CA) gave $250K to American Mission · $250KCondorcetCondorcetCompany or group · $100KCustom Management ServicesCustom Management ServicesCompany or group · $50,000Lonsdale Enterprises (CA)Lonsdale Enterprises (CA)Company or group · $250KSouth Dakota ConservativePACSouth Dakota Conservative PACGroup · $550KAmerican MissionAmerican MissionGroup · $230KBrian BengsBrian BengsCandidate · $550KMike RoundsMike RoundsCandidate · $230K
  • South Dakota Conservative PAC spent opposing Brian Bengs · $550K
  • American Mission spent supporting Mike Rounds · $230K
  • Condorcet gave to South Dakota Conservative PAC · $100K
  • Custom Management Services gave to South Dakota Conservative PAC · $50,000
  • Lonsdale Enterprises (CA) gave to American Mission · $250K
GaveSpent supportingSpent opposingSwipe to see the whole map.

Group

South Dakota Conservative PAC

  • South Dakota Conservative PAC spent $550K opposing Brian Bengs$550K
  • Condorcet gave $100K to South Dakota Conservative PAC$100K
  • Custom Management Services gave $50,000 to South Dakota Conservative PAC$50,000
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