Election Day, Nov 3 9 daysSenate D 78%House D 93%Governors D 86%Forecast updated Oct 25

How healthy is each campaign, and how does each side win? A health score for both campaigns in every Senate, governor and contested House race, and the path to victory for each side.

Senate · South Dakota

South Dakota Senate

Brian Bengs, independent vs Mike Rounds

ForecastR +16.2
Independent1%
Republican99%
RatingSafe R
Full forecast
Brief me as

Neutral view. Pick a side and the War Room briefs you as that campaign's operative.

Vital signs

Campaign health, 0 to 100, from public money, outside spending, ballots and activity
IndependentBrian BengsCriticalBase 15, minus 4 for liabilities
110100
  • Money weight 2532

    Raised $1.7M against $3.7M for Mike Rounds.

  • Cash weight 202

    $51K in the bank against $2.7M for Mike Rounds. As of 06/30/2026.

  • Air cover weight 150

    Outside groups spent $0 helping Brian Bengs and $1.4M helping Mike Rounds.

  • Early vote weight 1519

    Registered Democrats cast 30% of the 49,438 ballots in South Dakota so far, against 53% for the other party. That is 3.9 points worse for Democrats than the forecast expected by now. Counts registration, not votes.

  • −4 Outmatched five to one in cash. $51K against $2.7M.
RepublicanMike RoundsStrong
780100
  • Money weight 2569

    Raised $3.7M against $1.7M for Brian Bengs.

  • Cash weight 2098

    $2.7M in the bank against $51K for Brian Bengs. As of 06/30/2026.

  • Air cover weight 15100

    Outside groups spent $1.4M helping Mike Rounds and $0 helping Brian Bengs.

  • Early vote weight 1581

    Registered Republicans cast 53% of the 49,438 ballots in South Dakota so far, against 30% for the other party. That is 3.9 points better for Republicans than the forecast expected by now. Counts registration, not votes.

  • Activity weight 1025

    $22K in Google political ads this cycle.

How each side wins

From the forecast, the polls, the county map, voter groups, money and ballots
If you work for Brian Bengs
  1. Close the gap

    Brian Bengs trails by 16.2 and wins 1% of simulations. Closing it takes about 31,043 voters switching sides, or 62,086 more net votes from new turnout.

  2. The range

    In 8 of 10 simulations the result lands between R +24.5 and R +7.0. Only an unusual polling error changes the winner.

  3. The polls

    The polls page average is R +11.5. Your best recent poll is Concord Public Opinion Partners (D) at R +1.8; your worst is Quantus Insights at R +19.0. 6 polls in the last 30 days.

  4. Turn out the base

    The biggest vote banks for Democrats: Minnehaha, a projected net 3,500 votes; Oglala Lakota, a projected net 2,503 votes; Todd, a projected net 1,426 votes. Every point of extra turnout here is worth more than persuasion anywhere else.

  5. Win the battlegrounds

    The large counties within 12 points: Minnehaha, D +4.2, 21.6% of the vote; Brookings, R +11.5, 3.6% of the vote; Roberts, R +4.2, 1.0% of the vote; Moody, R +10.3, 0.7% of the vote.

  6. Where you run behind the 2024 map

    Against the 2024 presidential vote, Brian Bengs runs furthest behind in Hughes, Brookings, Lincoln. That is where the forecast sees voters who backed your side two years ago and have not come back yet.

  7. The coalition levers

    Groups big enough to move the race: White voters, 88% of voters, 41 to 59, where a 5 point gain is worth 4.42 points; Voters who cast ballots in 2022 and 2024, 72% of voters, 44 to 56, where a 5 point gain is worth 3.62 points; Voters who find daily costs hard to afford, 63% of voters, 48 to 52, where a 5 point gain is worth 3.13 points.

  8. Where you lose ground

    The forecast's worst groups for Brian Bengs: Immigration voters 21 to 79, Men 40 to 60, Small counties 40 to 60. Cutting the loss here is often cheaper than winning new groups.

  9. The money

    $51K cash against $2.7M. Outspent: lean on earned media, digital, field and the outside groups, and pick the two or three media markets that decide it.

  10. The early vote

    Registered Democrats cast 30% of the 49,438 ballots in South Dakota so far, against 53% for the other party. That is 3.9 points worse for Democrats than the forecast expected by now.

  11. What the ballots so far say

    The early vote has moved this forecast 1.1 points away from Brian Bengs. Election Day has to make it up: the remaining vote must break harder your way than the forecast expects.

  12. Mike Rounds's strongest asset

    Air cover: Outside groups spent $1.4M helping Mike Rounds and $0 helping Brian Bengs.

If you work for Mike Rounds
  1. Protect the lead

    Mike Rounds leads by 16.2 in the forecast and wins 99% of simulations. The cushion is about 62,086 votes; a one point swing is about 1,919 voters changing sides.

  2. The range

    In 8 of 10 simulations the result lands between R +7.0 and R +24.5. Only an unusual polling error changes the winner.

  3. The polls

    The polls page average is R +11.5. Your best recent poll is Quantus Insights at R +19.0; your worst is Concord Public Opinion Partners (D) at R +1.8. 6 polls in the last 30 days.

  4. Turn out the base

    The biggest vote banks for Republicans: Pennington, a projected net 7,868 votes; Lincoln, a projected net 6,057 votes; Meade, a projected net 4,850 votes. Every point of extra turnout here is worth more than persuasion anywhere else.

  5. Win the battlegrounds

    The large counties within 12 points: Minnehaha, D +4.2, 21.6% of the vote; Brookings, R +11.5, 3.6% of the vote; Roberts, R +4.2, 1.0% of the vote; Moody, R +10.3, 0.7% of the vote.

  6. Where you run behind the 2024 map

    Against the 2024 presidential vote, Mike Rounds runs furthest behind in Turner, Minnehaha, Custer. That is where the forecast sees voters who backed your side two years ago and have not come back yet.

  7. The coalition levers

    Groups big enough to move the race: White voters, 88% of voters, 59 to 41, where a 5 point gain is worth 4.42 points; Voters who cast ballots in 2022 and 2024, 72% of voters, 56 to 44, where a 5 point gain is worth 3.62 points; Voters who find daily costs hard to afford, 63% of voters, 52 to 48, where a 5 point gain is worth 3.13 points.

  8. Where you lose ground

    The forecast's worst groups for Mike Rounds: Asian and other voters 27 to 73, 2024 nonvoters and third party voters 32 to 68, Corruption voters 35 to 65. Cutting the loss here is often cheaper than winning new groups.

  9. The money

    $2.7M cash against $51K. Spend it early on persuasion television in the battleground counties and keep a reserve for the last week.

  10. The early vote

    Registered Republicans cast 53% of the 49,438 ballots in South Dakota so far, against 30% for the other party. That is 3.9 points better for Republicans than the forecast expected by now.

  11. What the ballots so far say

    The early vote has moved this forecast 1.1 points toward Mike Rounds. Bank it: chase the remaining mail ballots and low propensity voters who have not voted.

  12. Brian Bengs's strongest asset

    Money: Raised $1.7M against $3.7M for Mike Rounds.

The map for Bengs

County projections from the forecast
Vote banksWhere the biggest net margins come from
CountyForecastVote shareNet D
MinnehahaI +4.221.6%+3,500
Oglala LakotaI +76.80.8%+2,503
ToddI +64.30.6%+1,426
ClayI +16.81.5%+949
BattlegroundsLarge counties within 12 points
CountyForecastVote shareNet D
MinnehahaI +4.221.6%+3,500
BrookingsR +11.53.6%-1,606
RobertsR +4.21%-158
MoodyR +10.30.7%-292
Behind the 2024 mapRunning furthest behind the last presidential vote
CountyForecastVote shareNet D
HughesR +29.12.1%-2,298
BrookingsR +11.53.6%-1,606
LincolnR +19.38.2%-6,057

The coalition

Bengs against Rounds among the groups that can move it, from the forecast's voter group estimates
Swing groups
  • White voters89% of voters · a 5 point gain is worth 4.4
    4159
  • Voters who cast ballots in 2022 and 202472% of voters · a 5 point gain is worth 3.6
    4456
  • Voters who find daily costs hard to afford63% of voters · a 5 point gain is worth 3.1
    4852
  • Small counties57% of voters · a 5 point gain is worth 2.9
    4160
Weakest groups
  • Immigration voters12% of voters · a 5 point gain is worth 0.6
    2179
  • Men48% of voters · a 5 point gain is worth 2.4
    4060
  • Small counties57% of voters · a 5 point gain is worth 2.9
    4160
BengsRounds

Scouting report

From the Watchdog people files, each line with its source
Brian Bengs

No researched file yet; this candidate is queued for the next people file batch.

Mike Rounds

No researched file yet; this candidate is queued for the next people file batch.

The forecast

Margin over recent runs
R +19.9I +2.021 runs agonow
Now
R +16.2
8 in 10 land between
R +7.0 and R +24.5
Polling average
R +11.5
Partisan lean
R +28.4
Early vote effect
R +1.1

Recent polls

Last 45 days
PollsterDays agoSampleResult
Public Opinion Strategies for Rounds (R)0500 LVR +13.7
Quantus Insights0630 LVR +19.0
Emerson College0803 LVR +7.2
Mason-Dixon for South Dakota News Watch and USD Chiesman Center1500 LVR +18.2
Concord Public Opinion Partners (D)7400 LVR +1.8
Zenith Research18500 LVR +5.6
Public Policy Polling (D)36629 RVR +4.2

Money and the air war

Reports as of 06/30/2026
BengsRounds
Raised$1.7M$3.7M
Spent$731K$2.3M
Cash on hand$51K$2.7M
Outside money for$0$1.4M
Google ads$0$22K
Follow the money

The early vote

South Dakota, through 2026-10-24
Ballots cast
49,438
Party data
Reported by the state
Ballot margin
R +22.3
Forecast expected
R +18.5
Against expectation
3.9 points better for Republicans

Party registration of who has voted, not how they voted.

Open the early vote tracker

Media watch

Who is putting this race in front of an audience

Nothing logged yet for this race.

Media watch

On the trail

Rallies and events, newest first

No stops logged yet for this race.

Races that move with this one

When the polls miss here, they tend to miss there too