U.S. Senate · Updated Oct 9
South Dakota Senate
Mike Rounds win chance
80%
Typical margin: Rounds by 8.5
Republican
Who's running
The numbers behind it
Campaign money
Mike Rounds
Raised $4.5M · $2.7M cash on hand · through Jun 30, 2026 · FEC filing ↗
Brian Bengs
Raised $782K · $51K cash on hand · through Jun 30, 2026 · FEC filing ↗
Julian C Beaudion
Raised $228K · $3K cash on hand · through Jun 30, 2026 · FEC filing ↗
Our model counts the money gap as worth 1.3 points to Mike Rounds. Even a 10× gap is worth at most 1.5.
Candidates' own committees only, from fec.gov. Third-quarter reports are due Oct 15.
How the numbers moved
- Oct 1Inside Elections: Solid RepublicanInside Elections
- Sep 23Cook Political Report: Solid RCook Political Report
- Jun 30Julian C Beaudion had raised $228KFEC filing
- Jun 30Brian Bengs had raised $782KFEC filing
- Jun 30Mike Rounds had raised $4.5MFEC filing
How we got this number
We blend the polling average (when there is one) with the race's fundamentals: past results, incumbency, the national mood and the money. Then we play the election out 40,000 times, with polling misses that move every race together, and count how often each side wins.
90% of the model's 40,000 simulated elections land between R+24.2 and D+7.7.
The polling average we use has it at R+7.5.
Our method ›