South Carolina Senate Odds: Ralph Norman Closing Gap with Darline Graham Ahead of Tuesday's Special Election
South Carolina Republicans decide the party’s U.S. Senate nominee on Tuesday, August 25, as interim Sen. Darline Graham faces Rep. Ralph Norman in a special primary runoff. Graham has led the prediction market throughout the race, but a sharp late move toward Norman has turned what once looked like a comfortable advantage into one of Tuesday night’s most competitive election markets.
Peter Alexis - August 25, 2026, 6:45 PM EDT
4 Minute ReadDarline Graham Odds-On Favorite to Replace Brother Lindsey Graham in South Carolina Republican Primary on Tuesday Night
The South Carolina Republican Senate runoff reaches its conclusion Tuesday night, with polls closing at 7:00 PM ET before results begin arriving. Polymarket still makes Graham the favorite at 58%, but Norman has climbed to 43% after gaining nine points, while Graham has fallen eight points as the market tightens ahead of the first reported votes.
More than $18.1 million has already traded on the market, giving Tuesday’s late movement some significance. Graham has been favored throughout the runoff and was trading closer to 70% only days ago, but Norman has steadily closed the gap as polling and political handicappers have increasingly portrayed the race as a toss-up rather than a comfortable Graham victory. A recent Trafalgar survey had the candidates essentially tied at 48%, while some Republican race analysts have suggested Norman could even hold a narrow advantage.
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South Carolina Senate Odds to Replace Graham
Candidate | Implied Probability |
|---|---|
Darline Graham | 58% |
Ralph Norman | 43% |
South Carolina Senate Republican Primary Candidate Breakdown
Darline Graham 58%
Graham entered the runoff from the stronger position after winning the August 11 special primary with 32.7% of the vote. Norman finished second at 24.6%, with Russell Fry taking 19.6% and Mark Sanford around 15%, leaving a massive portion of the Republican electorate available to be redistributed in the head-to-head runoff.
Her biggest advantage remains the political machine behind her. President Donald Trump endorsed Graham shortly after she entered the race and has actively campaigned for her, while MAGA Inc. spent more than $800,000 supporting her candidacy. Sen. Tim Scott and Fry have also backed Graham, giving her endorsements from several of the state's most influential Republicans.
Graham also demonstrated a broader geographic base in the first round. She finished either first or second in all 46 counties and won 28 of them, giving her a much wider statewide footprint than Norman. That matters in a runoff where turnout can fall sharply and an established get-out-the-vote operation becomes increasingly important.
The problem is that Graham has endured a difficult final week. Her debate performance became a major storyline after she struggled with questions about foreign policy and national security, an issue Norman has used to emphasize the experience gap between the candidates. The late controversy appears to have contributed to the market moving away from a candidate who had previously looked much safer.
Ralph Norman 43%
Norman's path is straightforward: consolidate the majority of voters who opposed Graham in the first round and dominate his strongest regions. Although he finished roughly eight points behind Graham on August 11, Graham received only about one-third of the overall vote. Nearly two-thirds of Republican primary voters chose somebody else, leaving Norman with a much larger available pool than his initial 24.6% suggests.
The five-term congressman also has a clear geographic base. Norman performed particularly well across the Upstate and won his home York County with nearly 49% of the vote in the original primary. To pull the upset, he will likely need huge margins in York and other conservative Upstate counties while improving enough in the Midlands and coastal areas where Graham performed better.
Norman is also running as the more experienced option. He has served in Congress since 2017 and is a member of the House Freedom Caucus, allowing him to argue that voters do not need to choose between a conservative candidate and someone prepared to immediately handle the responsibilities of the Senate. He has picked up support from prominent Republicans including Nikki Haley while continuing to emphasize his own conservative record despite Trump backing Graham.
That message appears to be gaining traction at exactly the right time. Graham led the prediction market throughout the runoff and held an advantage of roughly two-to-one as recently as the weekend, but Norman moving into the low-40% range means traders no longer view his victory as a major upset.
Why the South Carolina Senate Odds Are Tightening
The first-round results make this a particularly difficult runoff to price. Graham won comfortably among a divided 10-candidate field, but 32.7% is far from the majority she needs Tuesday. The central question is where the Fry, Sanford and other eliminated-candidate voters go in a binary choice between Graham and Norman.
Graham has the stronger endorsement network, Trump’s support and the first-round advantage. Norman has the experience argument, a motivated regional base and potentially more natural room to grow among voters who deliberately chose someone other than Graham two weeks ago.
Turnout adds another layer. Roughly 45,000 ballots had already been cast before Election Day, but runoff electorates are often smaller and more difficult to model than the original primary electorate. South Carolina also automatically recounts statewide races decided by 1% or less, which could become relevant if the late polling is correct and Tuesday produces an extremely narrow finish.
Can Ralph Norman Steal the Runoff?
A 43% market probability still makes Norman the underdog, but this no longer looks like a race where Graham's earlier lead should be treated as secure.
Graham's 58% price is supported by her eight-point first-round victory, broad statewide performance and formidable endorsement operation. Norman's case rests on something different: most voters did not support Graham in the first round, late polling has shown essentially no separation between the candidates and the market itself has moved dramatically toward him as Election Day approached.
The first results should quickly reveal whether that move was justified. If Norman posts overwhelming margins in York, Greenville, Spartanburg and the broader Upstate while remaining competitive in Graham's stronger counties, the 43% price could disappear quickly. If Graham maintains her first-round geographic advantage while absorbing a meaningful portion of Fry's voters, her early market lead will have been justified.
For a race that spent most of the runoff looking like Graham's to lose, Tuesday night now appears genuinely capable of going either way.
- Upset Pick: Ralph Norman (43%) Bet on the South Carolina Senate Odds with Polymarket Here
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