Short Answer

Both the model and the market overwhelmingly agree that Darline Graham is most likely to win the South Carolina Republican Senate special primary, with only minor residual uncertainty.

1. Market Behavior & Drivers

This contract shows a clear upward trend, with the probability of a 'YES' outcome moving from a starting price of 63.0% to a current level of 86.0%. The market experienced significant volatility, trading within a wide range of 39.0% to 92.0%. A key inflection point occurred around the August 11 primary. Before the vote, the price saw a sharp, unexplained 10.0 percentage point drop on August 6. Following the primary, the contract established a new support level above 80.0%, with the post-election peak of 92.0% acting as near-term resistance.
The primary driver for price action was the result of the August 11 special primary. On August 12, news reports projected Darline Graham had secured the top spot for the runoff, causing an immediate 11.0 percentage point spike from 67.0% to 78.0%. This momentum continued through August 14, with another 9.0 point jump to 91.0% as the market fully priced in the official outcome, which placed Ralph Norman as the second-place finisher. The primary effectively resolved market uncertainty, repricing the contract from a competitive race to one with a clear frontrunner.
Total traded volume of over 2.8 million contracts indicates substantial market interest. Volume appears to have been highest during periods of uncertainty, such as the price dip around August 8. The lower volume seen after August 15 suggests that conviction firmed up after the primary results were known, with less speculative trading. The current price of 86.0% reflects strong market sentiment that the leading candidate from the primary will win the subsequent runoff.
  • Darline Graham appears favored despite limited new runoff data.
  • Graham and Ralph Norman advanced in the August 11 special primary.
  • The August 25 runoff has no reported endorsements from Mace or McMaster.

Who Wins and Why

Outcome Market Model Why
Darline Graham 86.0% 91.4% Darline Graham leads with strong support in current polling, making her the likely winner.
Ralph Norman 14.0% 5.6% Ralph Norman remains a distant challenger, trailing significantly in available support.

Current Context

On August 11, 2026, no candidate secured more than 50 percent of the vote in the South Carolina Republican Senate special primary, preventing an outright win [1][2][3][4][5][6]. The primary will proceed to a runoff election on August 25, 2026, between Senator Darline Graham and U.S. Representative Ralph Norman [1][2][7]. Senator Graham received 32.71% of the vote, while Representative Norman garnered 24.63% of the vote; both were the top two vote-getters and will contest the runoff [4][8][5].
Senator Lindsey Graham's death necessitated the special election. The special election was initiated following the death of U.S. Senator Lindsey Graham on July 11, 2026 [1][9][2][10][11]. Darline Graham, the late Senator's sister, had been appointed to serve the remainder of his term [1][9][2]. The winner of the August 25 Republican runoff will advance to face Democratic nominee Dr. Annie Andrews in the general election on November 3, 2026 [1][9][2].
Sources (11)
  1. 1Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  2. 2Graham to face Norman Aug. 25 in GOP Senate primary runoff - Statehousecharlestoncitypaper.com
  3. 3Darline Graham, Ralph Norman head to runoff in special GOP Senate primary in South Carolina, AP projectswbtv.com
  4. 42026 South Carolina US Senate | Live Election Resultsvotes.decisiondeskhq.com
  5. 5United States Senate election in South Carolina, 2026...ballotpedia.org
  6. 6United States Senate election in South Carolina, 2026ballotpedia.org
  7. 7In South Carolina, Sen. Darline Graham advances to a GOP special primary runoff for U.S. Senate | South Carolina Public Radiosouthcarolinapublicradio.org
  8. 8United States Senate election in South Carolina, 2026...ballotpedia.org
  9. 9South Carolina GOP voters in special primary for the late Sen. Lindsey Graham's seat | AP Newsapnews.com
  10. 10Lindsey Graham's death will set off a special primary election for a Senate seat that's open for the second time since 1956 - Ballotpedia Newsnews.ballotpedia.org
  11. 11Lindsay Graham is the fifth U.S. Senator to die during a re-election campaign since 1918 - Ballotpedia Newsnews.ballotpedia.org

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Significant Price Movements

Notable price changes detected in the chart, along with research into what caused each movement.

Outcome: Ralph Norman

📉 August 14, 2026: 10.0pp drop

Price decreased from 19.0% to 9.0%

What happened: The primary driver of Ralph Norman's prediction market price drop was the official outcome of the South Carolina Republican Senate special primary on August 11, 2026. The results, publicly known by August 12, revealed that no candidate won outright, and Norman placed second with 24.63% of the vote, advancing to a runoff against Darline Graham (32.71%) scheduled for August 25, 2026 [1]. This confirmed Norman had not won the primary directly, leading to a significant reassessment of his likelihood of being the eventual "winner" and causing the price decline by August 14, 2026. Social media was irrelevant, as no evidence of related activity was found.

Outcome: Darline Graham

📈 August 12, 2026: 11.0pp spike

Price increased from 67.0% to 78.0%

What happened: The primary driver of the 11.0 percentage point spike in Darline Graham's prediction market price on August 12, 2026, was the official news reporting of the South Carolina Republican Senate special primary election results. On August 12, 2026, major news outlets projected that Darline Graham, having secured approximately 32.7%–33% of the vote, finished first and advanced to a runoff election against Ralph Norman [2][3][4][5]. This confirmation of her leading position and advancement to the runoff, establishing her as the frontrunner for the nomination, coincided directly with the prediction market price movement [2][3][4]. Social media was irrelevant, as no specific activity or viral narratives were found to have driven this price change [6].

📉 August 06, 2026: 10.0pp drop

Price decreased from 58.0% to 48.0%

What happened: The provided web research offers no evidence of Darline Graham experiencing a 10.0 percentage point drop in support related to a specific catalyst event on August 6, 2026 [7]. Instead, news reports describe Darline Graham as a leading candidate who advanced to an August 25 runoff following the August 11, 2026, special Republican primary [1][8][9][7][10]. Given the absence of supporting information for the described market movement, the primary driver cannot be identified based on the available sources [7]. Consequently, social media activity was irrelevant as a primary driver, contributing accelerant, or noise for this unsupported market event.
Sources (10)
  1. 1Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  2. 2South Carolina special election results for Republican Senate primaryusatoday.com
  3. 3Darline Graham and Ralph Norman advance to runoff in South Carolina GOP Senate primary, CBS News projects - CBS Newscbsnews.com
  4. 4Darline Graham, Ralph Norman head to runoff in special GOP Senate primary in South Carolina, AP projectswbtv.com
  5. 52026 South Carolina US Senate | Live Election Resultsvotes.decisiondeskhq.com
  6. 6Darline Graham shoots ahead in special primary pollwonderwall.com
  7. 7Darline Graham advances to runoff to replace brother Lindsey Grahamwashingtonexaminer.com
  8. 8Graham to face Norman Aug. 25 in GOP Senate primary runoff - Statehousecharlestoncitypaper.com
  9. 9Darline Graham and Ralph Norman advance to runoff in special GOP primary • SC Daily Gazettescdailygazette.com
  10. 10United States Senate election in South Carolina, 2026...ballotpedia.org

4. Market Data

Contract Snapshot

This market determines the winner of the South Carolina Republican Senate special primary. A "Yes" contract for a specific candidate will resolve to $1 if that candidate wins the primary, while a "No" contract for that candidate will resolve to $1 if they do not win. The market opens on August 25, 12:00 am EDT, with a maximum payout date of August 11, 2027.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
Darline Graham $0.87 $0.14 86%
Ralph Norman $0.15 $0.86 14%

Market Discussion

No single winner emerged from the August 11, 2026, South Carolina Republican special Senate primary, as no candidate achieved a majority [1][2][3][4][5][6][7]. Consequently, Darline Graham, who received approximately 32.7% of the vote, and U.S. Representative Ralph Norman, with about 24.6%–24.7% of the vote, advanced to a runoff election scheduled for August 25, 2026 [1][2][3][8][4][5][6][7].

Sources (8)
  1. 1South Carolina GOP voters in special primary for the late Sen. Lindsey Graham's seat | AP Newsapnews.com
  2. 2South Carolina special election results for Republican Senate primaryusatoday.com
  3. 3Graham to face Norman Aug. 25 in GOP Senate primary runoff - Statehousecharlestoncitypaper.com
  4. 4United States Senate election in South Carolina, 2026...ballotpedia.org
  5. 5United States Senate election in South Carolina, 2026ballotpedia.org
  6. 6Election results, 2026ballotpedia.org
  7. 7United States Senate election in South Carolina, 2026...ballotpedia.org
  8. 8Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com

5. What does the geographic distribution of votes from the August 11 primary reveal about the core support bases for Darline Graham and Ralph Norman?

Darline Graham Vote32.7% (approximately) [1][2][3][4][5][6]
Ralph Norman Vote24.7% (approximately) [1][2][3][4][5]
Runoff DateAugust 25, 2026 [1][2][3][4][5][6][7]
Darline Graham and Ralph Norman advanced in the South Carolina Republican special Senate primary. Held on August 11, 2026, this primary saw Graham and Norman secure the top two positions, indicating strong initial support among the electorate. Both candidates are set to proceed to an August 25 runoff election [1][2][3][4][5][6][7].
Darline Graham demonstrated strong support across several counties, receiving approximately 32.7% of the total vote [1][2][3][4][5][6]. Her core support base was particularly evident in counties such as Allendale, where she garnered 48.3% of the vote, as well as Beaufort, Aiken, Charleston, Dorchester, Jasper, Clarendon, Greenwood, and Lexington counties. This geographic distribution highlights a specific regional concentration of Graham's support [1][2][3][4][5][6].
Ralph Norman's support concentrated in different upstate regions, securing approximately 24.7% of the vote [1][2][3][4][5]. His strongest performances were observed in counties like Anderson, where he received 32.7% of the vote, along with Greenville, York, Newberry, and Spartanburg [3][6]. The distinct voting patterns suggest that Norman also commands a geographically focused base of support among voters.
Sources (7)
  1. 1South Carolina U.S. Senate Special Primary Election Resultsnytimes.com
  2. 2South Carolina special election results for Republican Senate primaryusatoday.com
  3. 3South Carolina Senate Primary Special Election 2026 Live Results: Graham, Norman, Fry and Morenbcnews.com
  4. 4Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  5. 5Darline Graham and Ralph Norman advance to runoff in South Carolina GOP Senate primary, CBS News projects - CBS Newscbsnews.com
  6. 62026 South Carolina US Senate | Live Election Resultsvotes.decisiondeskhq.com
  7. 7Rep. John Larson becomes the ninth U.S. House incumbent to lose a primary this year to a non-incumbent - Ballotpedia Newsnews.ballotpedia.org

6. What do public polling and fundraising data released since the August 11 primary suggest about the potential outcome of the Graham-Norman runoff?

Darline Graham Primary Vote32.71% (August 11, 2026) [1][2][3]
Ralph Norman Primary Vote24.63% (August 11, 2026) [1][2][3]
Runoff Election DateAugust 25 [1][2][3]
Darline Graham is favored despite limited new data on the runoff. The August 11, 2026, special Republican primary for the late U.S. Senator Lindsey Graham's seat concluded with Darline Graham (32.71%) and U.S. Representative Ralph Norman (24.63%) advancing to an August 25 runoff, as no candidate achieved more than 50% of the vote [1][2][3]. Since the August 11 primary, no public polling or fundraising data has been released that definitively indicates the outcome of the August 25 runoff [4]. However, Darline Graham is considered the frontrunner, a perception supported by her strong primary performance and consistent favorable positioning in prediction markets, which suggest high confidence in her eventual nomination [5][6].
Both candidates have received significant endorsements since the primary. Following the initial primary results, Darline Graham garnered endorsements from prominent political figures, including President Donald Trump, Senator Tim Scott, and former primary opponent Russell Fry [5]. Ralph Norman has also secured support from notable individuals such as Nikki Haley and the Freedom Caucus [7].
Sources (7)
  1. 1Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  2. 2South Carolina Senate Primary Special Results 2026nbcnews.com
  3. 32026 South Carolina US Senate | Live Election Resultsvotes.decisiondeskhq.com
  4. 4Trump praises Darline Graham as she... - AP Newsroomnewsroom.ap.org
  5. 5Takeaways as Darline Graham faces Ralph Norman for Senatepostandcourier.com
  6. 6https://polymarket.com/event/south-carolina-republican-senate-special-primary-winner-20260712135206676?r=cbpmpolymarket.com
  7. 7SC Senate runoff endorsements: Who's backing Darline Graham and Ralph Norman before Aug. 25wistv.com

7. Which endorsements from former primary candidates like Nancy Mace or Henry McMaster could significantly influence voter alignment before the August 25 runoff?

Runoff DateAugust 25, 2026 [1][2][3][4]
Darline Graham Initial Primary Vote~32.71% [1][3][5]
Ralph Norman Initial Primary Vote~24.63% [1][3][5]
No reported endorsements exist from Mace or McMaster for the Senate runoff. As of August 15, 2026, research indicates no documented endorsements from former primary candidates like Nancy Mace or Governor Henry McMaster specifically for either Darline Graham or Ralph Norman in the South Carolina Republican special Senate primary runoff [6][7][8][9]. Therefore, the available information does not provide insight into how their endorsements could significantly influence voter alignment in this contest [6][7][8][9]. Nancy Mace is currently a gubernatorial candidate in the 2026 election cycle, and both she and Governor McMaster participated in a separate gubernatorial primary in June [6][7][8][9].
The special Senate runoff election is scheduled for August 25. This South Carolina Republican special Senate primary runoff will feature candidates Darline Graham and Ralph Norman on August 25, 2026 [1][2][3][4]. The special primary became necessary following the death of U.S. Senator Lindsey Graham on July 11, 2026 [6][10]. In the initial special primary held on August 11, 2026, Darline Graham secured approximately 32.71% of the vote, while Ralph Norman received about 24.63% [1][3][5]. The victor of the August 25 runoff will proceed to face Democrat Annie Andrews in the upcoming November general election [6][10].
Sources (10)
  1. 1United States Senate election in South Carolina, 2026...ballotpedia.org
  2. 2United States Senate election in South Carolina, 2026ballotpedia.org
  3. 3United States Senate election in South Carolina, 2026...ballotpedia.org
  4. 4South Carolina elections, 2026ballotpedia.org
  5. 52026 South Carolina US Senate | Live Election Resultsvotes.decisiondeskhq.com
  6. 6Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  7. 7Lindsey Graham's death will set off a special primary election for a Senate seat that's open for the second time since 1956 - Ballotpedia Newsnews.ballotpedia.org
  8. 8Endorsements by Henry McMasterballotpedia.org
  9. 9Rep. Nancy Mace becomes the eighth Republican representative to announce a gubernatorial bid for 2026 - Ballotpedia Newsnews.ballotpedia.org
  10. 10South Carolina holds special primary to replace Lindsey Graham | AP Newsapnews.com

8. How do Darline Graham and Ralph Norman compare on key policy positions and endorsements ahead of the August 25 runoff?

Darline Graham primary vote share32.71% (August 11, 2026) [1]
Ralph Norman primary vote share24.63% (August 11, 2026) [1]
Prediction market favoriteDarline Graham (consistently) [2][3][4]
Darline Graham and Ralph Norman advanced to a Republican Senate runoff. Both candidates secured spots in the August 25, 2026, special primary runoff after neither achieved 50% of the vote in the initial August 11 primary [5][6][7][8][9][10][1][11]. Darline Graham, sister of the late Sen. Lindsey Graham, has campaigned on her commitment to her brother's conservative agenda and has been praised by Donald Trump [7][11][5]. U.S. Rep. Ralph Norman emphasizes his "proven conservative" credentials and is characterized as a party hardliner [7][12]. Specific policy positions beyond these general conservative descriptions were not detailed in the provided information.
Graham led Norman in the initial primary vote. In the August 11, 2026, primary, Darline Graham received 32.71% of the vote, while Ralph Norman garnered 24.63% [1]. Following these results, prediction markets have consistently indicated a favorability towards Darline Graham to win the upcoming primary runoff [2][3][4].
Sources (12)
  1. 12026 South Carolina US Senate | Live Election Resultsvotes.decisiondeskhq.com
  2. 2https://polymarket.com/event/south-carolina-republican-senate-special-primary-winner-20260712135206676?r=cbpmpolymarket.com
  3. 3August 11, 2026: South Carolina Republican Senate special primary winner Prediction Marketrobinhood.com
  4. 4South Carolina Republican Senate Special Primary Winner | W.E.T.worldeventtrading.com
  5. 5Darline Graham and Ralph Norman advance to runoff in South Carolina GOP Senate primary, CBS News projects - CBS Newscbsnews.com
  6. 6Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  7. 7Graham to face Norman Aug. 25 in GOP Senate primary runoff - Statehousecharlestoncitypaper.com
  8. 8United States Senate election in South Carolina, 2026...ballotpedia.org
  9. 9United States Senate election in South Carolina, 2026ballotpedia.org
  10. 10United States Senate election in South Carolina, 2026...ballotpedia.org
  11. 11Trump praises Darline Graham as she... - AP Newsroomnewsroom.ap.org
  12. 12Takeaways as Darline Graham faces Ralph Norman for Senatepostandcourier.com

9. What is the historical precedent in South Carolina for runoff election outcomes when an appointed incumbent is being challenged?

Historical Incumbent Runoff Win1941 special election, appointed U.S. Senator Burnet R. Maybank won Democratic nomination runoff [1][2][3]
SC Primary Runoff TriggerNo candidate receives a majority of the vote, top two advance [4][5][6]
Incumbent Advantage in RunoffsSignificantly reduced, sometimes approaching a toss-up scenario [7]
South Carolina has a precedent for appointed incumbents winning runoffs. This occurred in the 1941 special election, where Burnet R. Maybank, serving as an appointed U.S. Senator and also an incumbent Governor, successfully secured the Democratic nomination in a runoff [1][2][3]. He emerged victorious against former Governor Olin D. Johnston in that contest [1][2][3].
Incumbents face reduced advantages when forced into South Carolina runoffs. In South Carolina, primary runoffs are necessitated when no candidate receives a majority of the vote in a multi-candidate field, compelling the top two finishers to advance to a second round [4][5][6]. While incumbents have historically shown varied success in these second-round elections, available data indicates that being forced into a runoff substantially diminishes their traditional electoral advantage, sometimes resulting in a near toss-up scenario [7].
Sources (7)
  1. 12026 United States Senate election in South Carolinaen.wikipedia.org
  2. 2Particle: Darline Graham and Ralph Norman Advance to August 25 GOP Runoff in South Carolinaparticle.news
  3. 3Name Power Meets Voter Pushback | News Hillnewshill.org
  4. 4Sanford defeats runoff primary challenger, advances to general election - Ballotpediaballotpedia.org
  5. 5South Carolina Attorney General election, 2022 - Ballotpediaballotpedia.org
  6. 6Three primaries headed for runoffs: South Carolina state executive primary elections review - Ballotpediaballotpedia.org
  7. 7Analysis of incumbency advantage in the 2014 school...ballotpedia.org

10. What Could Change the Odds

Key Catalysts

Prediction market catalysts for the 2026 elections include presidential approval ratings, economic performance metrics such as inflation and unemployment, and generic ballot polling [1][2]. Special election outcomes serve as real-time market repricing events [1][2]. As of August 2026, prediction markets generally favor a split Congress, with forecasts assigning Democrats approximately 60-80% probability for the House and Republicans approximately 55-60% probability for the Senate [3][4][2].
A key immediate event is the South Carolina Republican Senate special primary runoff. No winner was decided in the August 11, 2026, primary, as no candidate secured over 50% of the vote [5][6]. The special primary runoff, featuring incumbent Darline Graham and U.S. Rep. Ralph Norman, is scheduled for August 25, 2026 [5][6][7][8].

Key Dates & Catalysts

  • Expiration: August 11, 2027
  • Closes: August 11, 2027
Sources (8)
  1. 1Midterm Election 2026: Polymarket Probability & Market Forecast - Trade the Outcometradetheoutcome.com
  2. 2Balance of Power: 2026 Midterms Odds & Prediction Market Analysis | CryptoSlatecryptoslate.com
  3. 32026 Midterm Elections Tracker: Live Markets vs. Pollsactionnetwork.com
  4. 42026 Midterm Election Odds: House and Senate Marketsinsidepredictions.com
  5. 5Darline Graham, Norman head to runoff in US Senate primarypostandcourier.com
  6. 6Graham to face Norman Aug. 25 in GOP Senate primary runoff - Statehousecharlestoncitypaper.com
  7. 7Who will replace Lindsey Graham? South Carolina election timeline releasedcounton2.com
  8. 8Election timeline for replacement of Republican U.S. Senatewpde.com

12. Historical Resolutions

Historical Resolutions: 9 markets in this series

Outcomes: 0 resolved YES, 9 resolved NO

Recent resolutions:

  • KXSCRSENS-26-MSAN: NO (Aug 12, 2026)
  • KXSCRSENS-26-HMCM: NO (Aug 12, 2026)
  • KXSCRSENS-26-TGOW: NO (Aug 12, 2026)
  • KXSCRSENS-26-SBES: NO (Aug 12, 2026)
  • KXSCRSENS-26-RFRY: NO (Aug 12, 2026)